1) A population is a set that includes all elements about which we wish to draw a conclusion. Answer: TRUE Difficulty: 1 Easy Topic: Populations, Samples, and Traditional Statistics Learning Objective: 01-07 Describe the difference between a population and a sample. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 2) If we examine some of the population measurements, we are conducting a census of the population. Answer: FALSE Explanation: A census is defined as examining all of the population measurements. Difficulty: 2 Medium Topic: Populations, Samples, and Traditional Statistics Learning Objective: 01-07 Describe the difference between a population and a sample. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 3) A random sample is selected so that every element in the population has the same chance of being included in the sample. Answer: TRUE Difficulty: 1 Easy Topic: Random Sampling and Three Case Studies That Illustrate Statistical Inference Learning Objective: 01-09 Explain the concept of random sampling and select a random sample. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 1 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 4) An example of a quantitative variable is the manufacturer of a car. Answer: FALSE Explanation: This is an example of a qualitative or categorical variable. Difficulty: 1 Easy Topic: Data Learning Objective: 01-02 Describe the difference between a quantitative variable and a qualitative variable. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 5) An example of a qualitative variable is the mileage of a car. Answer: FALSE Explanation: This is an example of a quantitative variable. Difficulty: 1 Easy Topic: Data Learning Objective: 01-02 Describe the difference between a quantitative variable and a qualitative variable. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 6) Statistical inference is the science of using a sample of measurements to make generalizations about the important aspects of a population of measurements. Answer: TRUE Difficulty: 2 Medium Topic: Populations, Samples, and Traditional Statistics Learning Objective: 01-08 Distinguish between descriptive statistics and statistical inference. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 7) Time series data are data collected at the same time period. Answer: FALSE Explanation: Time series data are collected over different time periods. Difficulty: 1 Easy Topic: Data Learning Objective: 01-03 Describe the difference between cross-sectional data and time series data. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 2 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 8) Cross-sectional data are data collected at the same or approximately the same point in time. Answer: TRUE Difficulty: 1 Easy Topic: Data Learning Objective: 01-03 Describe the difference between cross-sectional data and time series data. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 9) Daily high temperature in a local community collected over a 30-day time period is an example of cross-sectional data. Answer: FALSE Explanation: Cross-sectional data are collected at the same point in time. This is an example of time series data. Difficulty: 1 Easy Topic: Data Learning Objective: 01-03 Describe the difference between cross-sectional data and time series data. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 10) The number of sick days taken by employees in 2008 for the top 10 technology companies is an example of time series data. Answer: FALSE Explanation: This is an example of cross-sectional data. Time series data are collected at different time periods. Difficulty: 1 Easy Topic: Data Learning Objective: 01-03 Describe the difference between cross-sectional data and time series data. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 3 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 11) The number of sick days per month taken by employees for the last 10 years at Apex Co. is an example of time series data. Answer: TRUE Difficulty: 2 Medium Topic: Data Learning Objective: 01-03 Describe the difference between cross-sectional data and time series data. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 12) A quantitative variable can also be referred to as a categorical variable. Answer: FALSE Explanation: Qualitative variables are also known as categorical variables. Difficulty: 1 Easy Topic: Data Learning Objective: 01-02 Describe the difference between a quantitative variable and a qualitative variable. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 13) In a data set of information on college business students, an example of an element is their cumulative GPA. Answer: FALSE Explanation: The college business students are the elements of the data set. The cumulative GPA is an example of a variable, which is a characteristic of an element (i.e., a college business student) in the data set. Difficulty: 2 Medium Topic: Data Learning Objective: 01-01 Define a variable. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 4 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 14) In an observational study, the variable of interest is called a response variable. Answer: TRUE Difficulty: 1 Easy Topic: Data Sources, Data Warehousing, and Big Data Learning Objective: 01-05 Identify the different types of data sources: existing data sources, experimental studies, and observational studies. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 15) In an experimental study, the aim is to manipulate or set the value of the response variable. Answer: FALSE Explanation: In experimental studies, the aim is to manipulate the factor(s), which may be related to the response variable. Difficulty: 2 Medium Topic: Data Sources, Data Warehousing, and Big Data Learning Objective: 01-05 Identify the different types of data sources: existing data sources, experimental studies, and observational studies. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 16) The science of describing the important aspects of a set of measures is called statistical inference. Answer: FALSE Explanation: This is the definition of descriptive statistics. Statistical inference is the science of using a sample of measurements to make generalizations about the population of measurements. Difficulty: 2 Medium Topic: Populations, Samples, and Traditional Statistics Learning Objective: 01-08 Distinguish between descriptive statistics and statistical inference. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 5 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 17) It is possible to use a random sample from a population to make statistical inferences about the entire population. Answer: TRUE Difficulty: 1 Easy Topic: Populations, Samples, and Traditional Statistics Learning Objective: 01-08 Distinguish between descriptive statistics and statistical inference. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 18) Processes produce outputs over time. Answer: TRUE Difficulty: 1 Easy Topic: Random Sampling and Three Case Studies That Illustrate Statistical Inference Learning Objective: 01-09 Explain the concept of random sampling and select a random sample. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 19) Selecting many different samples and running many different tests can eventually produce a result that makes a desired conclusion be true. Answer: FALSE Explanation: Using different samples and tests to produce a desired conclusion does not make the conclusion true. Difficulty: 2 Medium Topic: Random Sampling and Three Case Studies That Illustrate Statistical Inference Learning Objective: 01-09 Explain the concept of random sampling and select a random sample. Bloom's: Understand AACSB: Analytical Thinking Accessibility: Keyboard Navigation 20) Using a nonrandom sample procedure in order to support a desired conclusion is an example of an unethical statistical procedure. Answer: TRUE Difficulty: 2 Medium Topic: Random Sampling and Three Case Studies That Illustrate Statistical Inference Learning Objective: 01-09 Explain the concept of random sampling and select a random sample. Bloom's: Understand AACSB: Analytical Thinking Accessibility: Keyboard Navigation 6 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 21) An individual collecting data directly through planned experimentation is obtaining primary data. Answer: TRUE Difficulty: 1 Easy Topic: Data Sources, Data Warehousing, and Big Data Learning Objective: 01-05 Identify the different types of data sources: existing data sources, experimental studies, and observational studies. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 22) Secondary data are data taken from an existing source. Answer: TRUE Difficulty: 1 Easy Topic: Data Sources, Data Warehousing, and Big Data Learning Objective: 01-05 Identify the different types of data sources: existing data sources, experimental studies, and observational studies. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 23) Data warehousing is defined as a process of centralized data management and retrieval. Answer: TRUE Difficulty: 1 Easy Topic: Data Sources, Data Warehousing, and Big Data Learning Objective: 01-06 Explain the basic ideas of data warehousing and big data. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 24) The term big data refers to the use of survey data by big business. Answer: FALSE Explanation: Big data is a term that arose from the huge capacity of data warehouses that contain massive amounts of data. Difficulty: 1 Easy Topic: Data Sources, Data Warehousing, and Big Data Learning Objective: 01-06 Explain the basic ideas of data warehousing and big data. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 7 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 25) In order to select a stratified random sample, we divide the population into overlapping groups of similar elements. Answer: FALSE Explanation: A stratified random sample is created by dividing the population into nonoverlapping groups. Difficulty: 2 Medium Topic: Stratified Random, Cluster, and Systematic Sampling Learning Objective: 01-12 Describe the basic ideas of stratified random, cluster, and systematic sampling. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 26) If we sample without replacement, we do not place the unit chosen on a particular selection back into the population. Answer: TRUE Difficulty: 2 Medium Topic: Random Sampling and Three Case Studies That Illustrate Statistical Inference Learning Objective: 01-09 Explain the concept of random sampling and select a random sample. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 27) By taking a systematic sample in which we select every 100th shopper arriving at a specific store, we are approximating a random sample of shoppers. Answer: TRUE Difficulty: 2 Medium Topic: Stratified Random, Cluster, and Systematic Sampling Learning Objective: 01-12 Describe the basic ideas of stratified random, cluster, and systematic sampling. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 8 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 28) A common practice in selecting a sample from a large geographic area is multistage cluster sampling. Answer: TRUE Difficulty: 2 Medium Topic: Stratified Random, Cluster, and Systematic Sampling Learning Objective: 01-12 Describe the basic ideas of stratified random, cluster, and systematic sampling. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 29) Stratification can at times be combined with multistage cluster sampling to develop an appropriate sample. Answer: TRUE Difficulty: 2 Medium Topic: Stratified Random, Cluster, and Systematic Sampling Learning Objective: 01-12 Describe the basic ideas of stratified random, cluster, and systematic sampling. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 30) In systematic sampling, the first element is randomly selected from the first (N/n) elements. Answer: TRUE Difficulty: 3 Hard Topic: Stratified Random, Cluster, and Systematic Sampling Learning Objective: 01-12 Describe the basic ideas of stratified random, cluster, and systematic sampling. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 31) A sampling error can occur because of incomplete information. Answer: TRUE Difficulty: 2 Medium Topic: More about Surveys and Errors in Survey Sampling Learning Objective: 01-13 Describe basic types of survey questions, survey procedures, and sources of error. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 32) The target population is the result of sampling from the original population that is of interest 9 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. to the researcher. Answer: FALSE Explanation: Target population is the entire population of interest. Difficulty: 2 Medium Topic: More about Surveys and Errors in Survey Sampling Learning Objective: 01-13 Describe basic types of survey questions, survey procedures, and sources of error. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 33) Errors of non-observation occur when data values are recorded incorrectly. Answer: FALSE Explanation: Errors of non-observation relate to population elements that are not observed. Difficulty: 2 Medium Topic: More about Surveys and Errors in Survey Sampling Learning Objective: 01-13 Describe basic types of survey questions, survey procedures, and sources of error. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 34) A recording error is an error of observation. Answer: TRUE Difficulty: 2 Medium Topic: More about Surveys and Errors in Survey Sampling Learning Objective: 01-13 Describe basic types of survey questions, survey procedures, and sources of error. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 10 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 35) A low response rate has no effect on the validity of a survey's findings. Answer: FALSE Explanation: Low response rates do affect the validity of a survey's results. Difficulty: 2 Medium Topic: More about Surveys and Errors in Survey Sampling Learning Objective: 01-13 Describe basic types of survey questions, survey procedures, and sources of error. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 36) Sampling error occurs because a characteristic of a random sample may not exactly equal the population characteristic that we are attempting to estimate. Answer: TRUE Difficulty: 2 Medium Topic: More about Surveys and Errors in Survey Sampling Learning Objective: 01-13 Describe basic types of survey questions, survey procedures, and sources of error. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 37) Convenience sampling is a type of probability sampling in which we select elements to sample because we believe they have the highest probability of responding. Answer: FALSE Explanation: Convenience sampling is not probability sampling. Convenience sampling is a type of sampling in which we select elements because they are easy or convenient to sample. Difficulty: 2 Medium Topic: Random Sampling and Three Case Studies That Illustrate Statistical Inference Learning Objective: 01-09 Explain the concept of random sampling and select a random sample. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 11 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 38) Judgment sampling is an example of convenience sampling. Answer: FALSE Explanation: Judgment sampling has an extremely knowledgeable individual select the sample. Voluntary sampling occurs when participants self-select, which is a form of convenience sampling, where elements are selected because they are easy or convenient to sample. Difficulty: 2 Medium Topic: Random Sampling and Three Case Studies That Illustrate Statistical Inference Learning Objective: 01-09 Explain the concept of random sampling and select a random sample. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 39) Judgment sampling occurs when a person who is extremely knowledgeable about the population under consideration selects the population elements that they feel are most representative of the population. Answer: TRUE Difficulty: 1 Easy Topic: Random Sampling and Three Case Studies That Illustrate Statistical Inference Learning Objective: 01-09 Explain the concept of random sampling and select a random sample. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 40) Business analytics is a new field that does not use traditional statistics to analyze big data. Answer: FALSE Explanation: Business analytics is an extension of traditional statistics. Difficulty: 2 Medium Topic: Business Analytics and Data Mining Learning Objective: 01-10 Explain some of the uses of business analytics and data mining. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 12 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 41) Prescriptive analytics involve methods used to find anomalies, patterns, and associations in data sets with the purpose of predicting future outcomes. Answer: FALSE Explanation: This is the definition of predictive analytics. Prescriptive analytics uses results from predictive analytics to recommend courses of action within the business. Difficulty: 2 Medium Topic: Business Analytics and Data Mining Learning Objective: 01-10 Explain some of the uses of business analytics and data mining. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 42) A population that consists of all the customers who will use the drive-thru of the local fast food restaurant is called a(n) ________. A) infinite population B) random sample population C) statistical population D) finite population Answer: D Explanation: It is a finite population because only a finite number of customers will use the drive-thru. An infinite population would be defined as the theoretical potential number of customers. Difficulty: 2 Medium Topic: Random Sampling and Three Case Studies That Illustrate Statistical Inference Learning Objective: 01-09 Explain the concept of random sampling and select a random sample. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 43) In ________ we select elements because they are easy to sample. A) random sampling B) convenience sampling C) judgment sampling D) probability sampling Answer: B Explanation: Random sampling, judgment sampling, and probability sampling are methods of sampling in which the selected elements may not be convenient to sample. Difficulty: 1 Easy Topic: Random Sampling and Three Case Studies That Illustrate Statistical Inference Learning Objective: 01-09 Explain the concept of random sampling and select a random sample. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 13 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 44) ________ sampling is where we know the chance that each element will be included in the sample, which allows us to make statistical inferences about the sample population. A) Convenience B) Voluntary C) Probability D) Judgment Answer: C Explanation: Convenience, voluntary, and judgment sampling should not be used to make valid statistical inferences about a population. Difficulty: 2 Medium Topic: Random Sampling and Three Case Studies That Illustrate Statistical Inference Learning Objective: 01-09 Explain the concept of random sampling and select a random sample. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 45) Which of the following is not a method of numerical descriptive analytics? A) factor analysis B) cluster analysis C) bullet graphs D) association learning Answer: C Explanation: Bullet graphs are a method of graphical descriptive analytics. Difficulty: 2 Medium Topic: Business Analytics and Data Mining Learning Objective: 01-10 Explain some of the uses of business analytics and data mining. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 14 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 46) ________ uses traditional or newer graphics to present visual summaries of business information. A) Nonparametric predictive analytics B) Parametric predictive analytics C) Prescriptive analytics D) Graphical descriptive analytics Answer: D Explanation: Predictive analytics (whether parametric or nonparametric) are methods used to predict values of a response variable on the basis of one or more predictor variables. Prescriptive analytics are techniques that combine external and internal constraints with results from descriptive or predictive analytics to recommend an optimal course of action. Difficulty: 1 Easy Topic: Business Analytics and Data Mining Learning Objective: 01-10 Explain some of the uses of business analytics and data mining. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 47) Which of the following is not a supervised learning technique in predictive analytics? A) linear regression B) factor analysis C) decision trees D) neural networks Answer: B Explanation: Factor analysis is an unsupervised learning technique because there is no specific response variable involved, which is a requirement for a supervised learning technique. Difficulty: 2 Medium Topic: Business Analytics and Data Mining Learning Objective: 01-10 Explain some of the uses of business analytics and data mining. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 15 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 48) Transactional data are now used by businesses as part of A) survey analysis. B) big data. C) descriptive statistics. D) experimental studies. Answer: B Explanation: By definition, big data are collected by business for effective decision making. Difficulty: 2 Medium Topic: Data Sources, Data Warehousing, and Big Data Learning Objective: 01-06 Explain the basic ideas of data warehousing and big data. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 49) ________ consists of a set of concepts and techniques that are used to describe populations and samples and to make statistical inferences about populations by using samples. A) Traditional statistics B) Random sampling C) Data mining D) Time series analysis Answer: A Explanation: Definition of traditional statistics. Difficulty: 1 Easy Topic: Populations, Samples, and Traditional Statistics Learning Objective: 01-08 Distinguish between descriptive statistics and statistical inference. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 16 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 50) When we are choosing a random sample and we do not place chosen units back into the population, we are A) sampling with replacement. B) sampling without replacement. C) using a systematic sample. D) using a voluntary response sample. Answer: B Explanation: Sampling with replacement occurs when a selected element is replaced before another sample is taken; systematic and voluntary response samples are not random. Difficulty: 2 Medium Topic: Random Sampling and Three Case Studies That Illustrate Statistical Inference Learning Objective: 01-09 Explain the concept of random sampling and select a random sample. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 51) Which of the following is a type of question used in survey research? A) dichotomous B) open-ended C) multiple-choice D) All of the other answers are correct. Answer: D Explanation: All three of the listed question types can be used in survey design. Difficulty: 2 Medium Topic: More about Surveys and Errors in Survey Sampling Learning Objective: 01-13 Describe basic types of survey questions, survey procedures, and sources of error. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 17 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 52) Methods for obtaining a sample are called A) sample surveys. B) probability sampling. C) random sampling. D) sampling designs. Answer: D Explanation: Sample surveys are the result of sampling designs. Random sampling, stratified random sampling, cluster sampling, and systematic sampling are sampling designs which are types of probability sampling. Difficulty: 2 Medium Topic: Stratified Random, Cluster, and Systematic Sampling Learning Objective: 01-12 Describe the basic ideas of stratified random, cluster, and systematic sampling. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 53) A ________ is a list of all the units in a population. A) sample B) frame C) census D) variable Answer: B Explanation: A sample can be only a part of a population; a census is the examination of the population and variable is a characteristic of an element of the population. Difficulty: 2 Medium Topic: Random Sampling and Three Case Studies That Illustrate Statistical Inference Learning Objective: 01-09 Explain the concept of random sampling and select a random sample. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 18 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 54) Nonoverlapping groups of similar elements in a population are called A) clusters. B) frames. C) strata. D) stages. Answer: C Explanation: Strata are groups within a population sample which do not overlap. Difficulty: 3 Hard Topic: Stratified Random, Cluster, and Systematic Sampling Learning Objective: 01-12 Describe the basic ideas of stratified random, cluster, and systematic sampling. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 55) A Yes or No question is ________. A) dichotomous B) evaluative C) open-ended D) systematic Answer: A Explanation: Dichotomous questions consist of only two possible responses. Difficulty: 2 Medium Topic: More about Surveys and Errors in Survey Sampling Learning Objective: 01-13 Describe basic types of survey questions, survey procedures, and sources of error. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 19 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 56) ________ occurs when some population elements are excluded from the process of selecting the sample. A) Nonresponse B) Error of observation C) Undercoverage D) Sample frame Answer: C Explanation: Exclusion of population elements in selection is not a result of nonresponse or error of observation because this occurs during the survey itself. Sampling error is a result of the survey process. Difficulty: 2 Medium Topic: More about Surveys and Errors in Survey Sampling Learning Objective: 01-13 Describe basic types of survey questions, survey procedures, and sources of error. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 57) ________ is the difference between a numerical descriptor of the population and the corresponding descriptor of the sample. A) Sampling error B) Nonobservation error C) Observation error D) Nonresponse Answer: A Explanation: Nonresponse, nonobservation and observation error occur during the survey process. Sampling error is a result of the survey process. Difficulty: 2 Medium Topic: More about Surveys and Errors in Survey Sampling Learning Objective: 01-13 Describe basic types of survey questions, survey procedures, and sources of error. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 20 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 58) Data that are collected by an individual through personally planned experimentation or observation are ________. A) secondary data B) quantitative data C) primary data D) variables Answer: C Explanation: By definition, primary data are collected while secondary data are from an existing source. Difficulty: 1 Easy Topic: Data Sources, Data Warehousing, and Big Data Learning Objective: 01-05 Identify the different types of data sources: existing data sources, experimental studies, and observational studies. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 59) A ratio variable has the following characteristic. A) qualitative B) inherently defined zero value C) categorical in nature D) predictable Answer: B Explanation: By definition, ratio variables are quantitative and have an absolute zero value. Difficulty: 1 Easy Topic: Ratio, Interval, Ordinal, and Nominative Scales of Measurement Learning Objective: 01-11 Identify the ratio, interval, ordinal, and nominative scales of measurement. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 21 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 60) Which of the following is a quantitative variable? A) the manufacturer of a cell phone B) a person's gender C) mileage of a car D) whether a person is a college graduate E) whether a person has a charge account Answer: C Explanation: A quantitative variable is measurable and noncategorical. Difficulty: 1 Easy Topic: Data Learning Objective: 01-02 Describe the difference between a quantitative variable and a qualitative variable. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 61) Which of the following is a categorical variable? A) air temperature B) bank account balance C) daily sales in a store D) whether a person has a traffic violation E) value of company stock Answer: D Explanation: A categorical variable is qualitative, not measured. Difficulty: 2 Medium Topic: Data Learning Objective: 01-02 Describe the difference between a quantitative variable and a qualitative variable. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 22 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 62) Measurements from a population are called A) elements. B) observations. C) variables. D) processes. Answer: B Explanation: By definition, elements are the members of the population and variables are characteristics of elements; a measurement (or observation) assigns a value to a variable for an element of the population. A process is a sequence of operations that takes inputs and turns them into outputs. Difficulty: 2 Medium Topic: Populations, Samples, and Traditional Statistics Learning Objective: 01-07 Describe the difference between a population and a sample. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 63) The two types of quantitative variables are A) ordinal and ratio. B) interval and ordinal. C) nominative and ordinal. D) interval and ratio. E) nominative and interval. Answer: D Explanation: Nominative and ordinal are types of qualitative variables. Difficulty: 2 Medium Topic: Ratio, Interval, Ordinal, and Nominative Scales of Measurement Learning Objective: 01-11 Identify the ratio, interval, ordinal, and nominative scales of measurement. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 23 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 64) Temperature (in degrees Fahrenheit) is an example of a(n) ________ variable. A) nominative B) ordinal C) interval D) ratio Answer: C Explanation: Temperature is quantitative (excludes nominative and ordinal), and the ratio of two temperatures is not meaningful. Difficulty: 2 Medium Topic: Ratio, Interval, Ordinal, and Nominative Scales of Measurement Learning Objective: 01-11 Identify the ratio, interval, ordinal, and nominative scales of measurement. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 65) Jersey numbers of soccer players is an example of a(n) ________ variable. A) nominative B) ordinal C) interval D) ratio Answer: A Explanation: Interval and ratio are quantitative variables; jersey numbers have no logical order. Difficulty: 2 Medium Topic: Ratio, Interval, Ordinal, and Nominative Scales of Measurement Learning Objective: 01-11 Identify the ratio, interval, ordinal, and nominative scales of measurement. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 24 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 66) The weight of a chemical compound used in an experiment that is obtained using a welladjusted scale represents a(n) ________ level of measurement. A) nominative B) ordinal C) interval D) ratio Answer: D Explanation: Nominative and ordinal are qualitative variables; weight creates logical ratios: 60 lb is twice as heavy as 30 lb. Difficulty: 2 Medium Topic: Ratio, Interval, Ordinal, and Nominative Scales of Measurement Learning Objective: 01-11 Identify the ratio, interval, ordinal, and nominative scales of measurement. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 67) An identification of police officers by rank would represent a(n) ________ level of measurement. A) nominative B) ordinal C) interval D) ratio Answer: B Explanation: Interval and ratio are quantitative variables, nominative is only a naming category, and police rank has order. Difficulty: 2 Medium Topic: Ratio, Interval, Ordinal, and Nominative Scales of Measurement Learning Objective: 01-11 Identify the ratio, interval, ordinal, and nominative scales of measurement. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 25 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 68) ________ is a necessary component of a runs plot. A) Observation over time B) Qualitative variable C) Random sampling of the data D) Cross-sectional data Answer: A Explanation: A runs plot is a graphical display of time series data. Difficulty: 2 Medium Topic: Data Learning Objective: 01-04 Construct and interpret a time series (runs) plot. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 69) ________ is the science of using a sample to make generalizations about the important aspects of a population. A) Time series analysis B) Descriptive statistics C) Random sample D) Statistical inference Answer: D Explanation: By definition, a time series is a study of data over time; descriptive statistics is the study of the measurements of population variables; a random sample is a data set. Difficulty: 1 Easy Topic: Populations, Samples, and Traditional Statistics Learning Objective: 01-08 Distinguish between descriptive statistics and statistical inference. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 26 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 70) College entrance exam scores, such as SAT scores, are an example of a(n) ________ variable. A) ordinal B) ratio C) nominative D) interval Answer: D Explanation: Nominative and ordinal are qualitative variables; college entrance exam scores have no meaningful ratio and no inherently defined zero value. Difficulty: 3 Hard Topic: Ratio, Interval, Ordinal, and Nominative Scales of Measurement Learning Objective: 01-11 Identify the ratio, interval, ordinal, and nominative scales of measurement. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 71) The number of miles a truck is driven before it is overhauled is an example of a(n) ________ variable. A) nominative B) ordinal C) interval D) ratio Answer: D Explanation: Nominative and ordinal are qualitative variables; miles driven can have a meaningful ratio. Difficulty: 2 Medium Topic: Ratio, Interval, Ordinal, and Nominative Scales of Measurement Learning Objective: 01-11 Identify the ratio, interval, ordinal, and nominative scales of measurement. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 27 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 72) A(n) ________ variable is a qualitative variable such that there is no meaningful ordering or ranking of the categories. A) ratio B) ordinal C) nominative D) interval Answer: C Explanation: Ratio and interval are quantitative variables; ordinal implies order or rank. Difficulty: 1 Easy Topic: Ratio, Interval, Ordinal, and Nominative Scales of Measurement Learning Objective: 01-11 Identify the ratio, interval, ordinal, and nominative scales of measurement. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 73) A person's telephone area code is an example of a(n) ________ variable. A) nominative B) ordinal C) interval D) ratio Answer: A Explanation: This is a qualitative variable without order; therefore, a nominative variable. Difficulty: 2 Medium Topic: Ratio, Interval, Ordinal, and Nominative Scales of Measurement Learning Objective: 01-11 Identify the ratio, interval, ordinal, and nominative scales of measurement. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 28 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 74) Any characteristic of a population unit is a(n) A) measurement. B) sample. C) observation. D) variable. Answer: D Explanation: Measurement and observation are methods attached to a variable; a sample is a subset of the units in a population. Difficulty: 2 Medium Topic: Data Learning Objective: 01-01 Define a variable. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 75) Examining all population measurements is called a ________. A) census B) frame C) sample D) variable Answer: A Explanation: By definition, a census looks at the entire population. Difficulty: 2 Medium Topic: Populations, Samples, and Traditional Statistics Learning Objective: 01-07 Describe the difference between a population and a sample. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 76) Any characteristic of an element is called a ________. A) set B) process C) variable D) census Answer: C Explanation: A process is a sequence of operations; a census looks at the entire population; set is related to population. Difficulty: 1 Easy Topic: Data Learning Objective: 01-01 Define a variable. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 29 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 77) The process of assigning a value of a variable to each element in a data set is called ________. A) sampling B) measurement C) experimental analysis D) observational analysis Answer: B Explanation: By definition, sampling is taking a portion of the population to measure; experimental and observational analysis are methods of obtaining data. Difficulty: 2 Medium Topic: Data Learning Objective: 01-01 Define a variable. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 78) A ________ is a display of individual measurements versus time. A) runs plot B) statistical analysis C) random sample D) measurement Answer: A Explanation: A runs plot is a graphical display of data over time. Difficulty: 1 Easy Topic: Data Learning Objective: 01-04 Construct and interpret a time series (runs) plot. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 30 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 79) Statistical ________ refers to using a sample of measurements and making generalizations about the important aspects of a population. A) sampling B) process C) analysis D) inference Answer: D Explanation: By definition, inference is taking a sample of data and its measurements and relating those measurements to the population as a whole. Difficulty: 2 Medium Topic: Populations, Samples, and Traditional Statistics Learning Objective: 01-08 Distinguish between descriptive statistics and statistical inference. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 80) A ________ is a subset of the units in a population. A) census B) process C) sample D) variable Answer: C Explanation: By definition, a census looks at an entire population; a variable is a characteristic of an element within the population; a process is a sequence of operations that produces elements of a population. Difficulty: 1 Easy Topic: Populations, Samples, and Traditional Statistics Learning Objective: 01-07 Describe the difference between a population and a sample. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 31 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 81) A ________ variable takes on values that are numbers on the real number line. A) qualitative B) quantitative C) categorical D) nominative Answer: B Explanation: Qualitative, categorical, and nominative variables are non-quantitative variables. Difficulty: 2 Medium Topic: Data Learning Objective: 01-02 Describe the difference between a quantitative variable and a qualitative variable. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 82) A sequence of operations that takes inputs and turns them into outputs is a ________. A) process B) statistical inference C) runs plot D) random sampling Answer: A Explanation: By definition, a runs plot is a graphical display; random sampling is a method of selecting a portion of a population; statistical inference is the science of using a sample of measurements to infer about the entire population. Difficulty: 1 Easy Topic: Random Sampling and Three Case Studies That Illustrate Statistical Inference Learning Objective: 01-09 Explain the concept of random sampling and select a random sample. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 32 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 83) A(n) ________ variable can have values that indicate into which of several categories of a population it belongs. A) qualitative B) quantitative C) ratio D) interval Answer: A Explanation: Quantitative, ratio, and interval all have similar definitions. Difficulty: 2 Medium Topic: Data Learning Objective: 01-02 Describe the difference between a quantitative variable and a qualitative variable. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 84) A set of all elements we wish to study is called a ________. A) sample B) process C) census D) population Answer: D Explanation: By definition, a census is the examination of all population measurements; a process is a sequence of operations; a sample is a subset of a population. Difficulty: 2 Medium Topic: Populations, Samples, and Traditional Statistics Learning Objective: 01-07 Describe the difference between a population and a sample. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 33 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 85) ________ refers to describing the important aspects of a set of measurements. A) Cross-sectional analysis B) Runs plot C) Descriptive statistics D) Time series analysis Answer: C Explanation: A runs plot and time series analysis both look at data over time; cross-sectional analysis looks at data collected at the same point in time. Difficulty: 2 Medium Topic: Populations, Samples, and Traditional Statistics Learning Objective: 01-08 Distinguish between descriptive statistics and statistical inference. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 86) The change in the daily price of a stock is what type of variable? A) qualitative B) ordinal C) random D) quantitative Answer: D Explanation: Qualitative and ordinal have similar definitions; random variables are all characteristics of a population element. Difficulty: 2 Medium Topic: Data Learning Objective: 01-02 Describe the difference between a quantitative variable and a qualitative variable. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 34 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 87) Data collected for a particular study are referred to as a data ________. A) variable B) measurement C) set D) element Answer: C Explanation: By definition, a variable is a characteristic of an element; a measurement assigns a value to a variable; an element is one unit of a population. Difficulty: 2 Medium Topic: Data Learning Objective: 01-01 Define a variable. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 88) A data set provides information about some group of individual ________. A) variables B) elements C) statistics D) measurements Answer: B Explanation: By definition, measurements assign values to a variable of an element; statistics is the science of describing aspects of a set of measurements; variables are characteristics of elements in a population. Difficulty: 2 Medium Topic: Data Learning Objective: 01-01 Define a variable. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 35 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 89) When the data being studied are gathered from a published source, this is referred to as a(n) ________. A) existing data source B) observational data source C) experimental data source D) cross-sectional data source Answer: A Explanation: By definition, an experimental data source is a collection of data where one is able to manipulate values; an observational data source is a collection of data where one is unable to control factors. Cross-sectional is not a defined data source but rather a way of analyzing or displaying the data that have been collected. Difficulty: 2 Medium Topic: Data Sources, Data Warehousing, and Big Data Learning Objective: 01-05 Identify the different types of data sources: existing data sources, experimental studies, and observational studies. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 90) One method of being sure a sample being studied can be used to make statistical inferences about the population is to select a A) judgment sample. B) voluntary response sample. C) convenience sample. D) probability sample. Answer: D Explanation: Runs plots are a way of looking at processes over time, which can then be used to make inferences about a population. Simply looking at descriptive statistics (of which, proportion and cross-sectional analysis are methods or procedures) is not sufficient to make inferences. Difficulty: 2 Medium Topic: Random Sampling and Three Case Studies That Illustrate Statistical Inference Learning Objective: 01-09 Explain the concept of random sampling and select a random sample. Bloom's: Apply AACSB: Reflective Thinking Accessibility: Keyboard Navigation 36 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 91) Which of the following is not an example of unethical statistical practices? A) inappropriate interpretation of statistical results B) using graphs to make statistical inferences C) improper sampling D) descriptive measures that mislead the user E) None of the other answers is correct. Answer: B Explanation: It is unethical to use methods or procedures designed to mislead the audience that is viewing the findings. Difficulty: 2 Medium Topic: Random Sampling and Three Case Studies That Illustrate Statistical Inference Learning Objective: 01-09 Explain the concept of random sampling and select a random sample. Bloom's: Understand AACSB: Analytical Thinking Accessibility: Keyboard Navigation 92) If we collect data on the number of wins each team in the NFL had during the 2011-12 season, we have ________ data. A) cross-sectional B) time series C) non-historical D) survey Answer: A Explanation: A time series is a collection of data taken over time, while a cross-section is a collection of data taken at the same point in time. Difficulty: 2 Medium Topic: Data Learning Objective: 01-03 Describe the difference between cross-sectional data and time series data. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 37 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 93) If we collect data on the number of wins the Dallas Cowboys earned each of the past 10 years, we have ________ data. A) cross-sectional B) time series C) non-historical D) survey Answer: B Explanation: A time series is a collection of data taken over time, while a cross-section is a collection of data taken at the same point in time. Difficulty: 2 Medium Topic: Data Learning Objective: 01-03 Describe the difference between cross-sectional data and time series data. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 94) A study is being conducted on the effect of gas price on the number of miles driven in a given month. Residents in two cities, one on the East Coast and one on the West Coast, are randomly selected and asked to complete a questionnaire on the type of car they drive, the number of miles they live from work, the number of children under 18 in their household, their monthly income, and the number of miles they have driven over the past 30 days. List the response variable(s). Answer: The response variable in this study is the number of miles driven over the past 30 days. Response variables are defined as the variable of interest in a study. Difficulty: 2 Medium Topic: Data Sources, Data Warehousing, and Big Data Learning Objective: 01-05 Identify the different types of data sources: existing data sources, experimental studies, and observational studies. Bloom's: Understand; Apply AACSB: Reflective Thinking Accessibility: Keyboard Navigation 38 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 95) A study is being conducted on the effect of gas price on the number of miles driven in a given month. Residents in two cities, one on the East Coast and one on the West Coast, are randomly selected and asked to complete a questionnaire on the type of car they drive, the number of miles they live from work, the number of children under 18 in their household, their monthly income, and the number of miles they have driven over the past 30 days. Is this an experimental or observational study? Answer: Observational study An observational study occurs when analysts are unable to control the factors of interest. An experimental study occurs when values of factors that are related to the variable of interest can be set or manipulated. Difficulty: 2 Medium Topic: Data Sources, Data Warehousing, and Big Data Learning Objective: 01-05 Identify the different types of data sources: existing data sources, experimental studies, and observational studies. Bloom's: Understand; Apply AACSB: Reflective Thinking Accessibility: Keyboard Navigation 96) A study is being conducted on the effect of gas price on the number of miles driven in a given month. Residents in two cities, one on the East Coast and one on the West Coast, are randomly selected and asked to complete a questionnaire on the type of car they drive, the number of miles they live from work, the number of children under 18 in their household, their monthly income, and the number of miles they have driven over the past 30 days. List the factor(s). Answer: Factors in this study are location of residence, type of car, number of miles from work, number of children under 18, and monthly income. Factors are related to the variable of interest. Difficulty: 2 Medium Topic: Data Sources, Data Warehousing, and Big Data Learning Objective: 01-05 Identify the different types of data sources: existing data sources, experimental studies, and observational studies. Bloom's: Understand; Apply AACSB: Reflective Thinking Accessibility: Keyboard Navigation 39 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 97) Looking at the runs plot of gasoline prices over the past 30 months, describe what it tells us about the price of gas during these 30 months. Answer: The price of gas peaked in the seventh month. The lowest price is observed around 20 to 21 months from the start of the data collection. At the end of the 30 months, gas price is beginning to show stability. Observing the rise and fall of a time series or runs plot. Difficulty: 2 Medium Topic: Data Learning Objective: 01-04 Construct and interpret a time series (runs) plot. Bloom's: Understand; Apply AACSB: Reflective Thinking Accessibility: Keyboard Navigation 40 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 98) Using the following data table of the average hours per week spent on Internet activities by 15- to 18-year-olds for the years 1999 to 2008, construct the runs plot and interpret. 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 13.5 15.0 16.5 17.7 18.2 19.3 19.5 19.9 20.1 20.4 Answer: Displaying the average hours spent on Internet activities graphically results in a time series or runs plot. An increase over time in the amount of time can be observed through either the graph or data. Difficulty: 2 Medium Topic: Data Learning Objective: 01-04 Construct and interpret a time series (runs) plot. Bloom's: Understand; Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 41 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 1) A stem-and-leaf display is a graphical portrayal of a data set that shows the data set's overall pattern of variation. Answer: TRUE Explanation: This kind of graph places the measurements in order from smallest to largest. Difficulty: 2 Medium Topic: Stem-and-Leaf Displays Learning Objective: 02-05 Construct and interpret stem-and-leaf displays. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 2) The relative frequency is the frequency of a class divided by the total number of measurements. Answer: TRUE Explanation: This is used when we wish to summarize the proportion (or fraction) of items in each class. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data; Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives.; 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 3) A bar chart is a graphic that can be used to depict qualitative data. Answer: TRUE Explanation: A bar chart is a graphic that depicts a frequency, relative frequency, or percent frequency distribution. Difficulty: 1 Easy Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 42 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 4) Stem-and-leaf displays and dot plots are useful for detecting outliers. Answer: TRUE Explanation: Since this graph places the measurements in order from smallest to largest, it allows the analyst to see all of the measurements in the data set. Difficulty: 2 Medium Topic: Stem-and-Leaf Displays; Dot Plots Learning Objective: 02-05 Construct and interpret stem-and-leaf displays.; 02-04 Construct and interpret dot plots. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 5) A scatter plot can be used to identify outliers. Answer: FALSE Explanation: A scatter plot is used to identify the relationship between two variables. Difficulty: 2 Medium Topic: Scatter Plots Learning Objective: 02-07 Examine the relationships between variables by using scatter plots. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 6) When looking at the shape of the distribution using a histogram, a distribution is skewed to the right when the left tail is shorter than the right tail. Answer: TRUE Explanation: This type of histogram has a high frequency number of data points on the right compared to the left side of the histogram. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 43 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 7) When we wish to summarize the proportion (or fraction) of items in a class, we use the frequency distribution for each class. Answer: FALSE Explanation: The relative frequency summarizes the proportion (or fraction) of items in a class. Frequency distribution shows actual counts of items in each class. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data; Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives.; 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 8) When establishing the classes for a frequency distribution, it is generally agreed that the more classes you use the better your frequency distribution will be. Answer: FALSE Explanation: Classes should be determined by the number of data measurements. Difficulty: 1 Easy Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 9) The cumulative frequency for a class will always be at least as large as the cumulative frequency for any class with a smaller upper boundary. Answer: TRUE Explanation: This is the number of measurements that are less than the upper boundary of the class. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 44 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 10) A frequency table includes row and column percentages. Answer: FALSE Explanation: Frequency tables include frequencies, relative frequency, and percent frequency. Cross-tabulation tables include row and column percentages. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data; Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives.; 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 11) When constructing a graphical display that utilizes categorical data, classes that have frequencies of 5 percent or less are usually combined together into a single category. Answer: TRUE Explanation: This is done so we can combine the categorical data in a way that is visually pleasing to read and analyze. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-02 Construct and interpret Pareto charts. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 12) In a Pareto chart, the bar for the "Other" category should be placed to the far left of the chart. Answer: FALSE Explanation: The bar to the far left of the Pareto chart will be the category with the highest frequency. Difficulty: 1 Easy Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-02 Construct and interpret Pareto charts. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 45 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 13) In the first step of setting up a Pareto chart, a frequency table should be constructed of the defects (or categories) in decreasing order of frequency. Answer: TRUE Explanation: The defect with the highest frequency will be at the top of the table and so forth. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-02 Construct and interpret Pareto charts. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 14) It is possible to create different interpretations of the same graphical display by simply using different captions. Answer: TRUE Explanation: It is all in the way that the analyzer would like to display and depict the data to the reader. Difficulty: 2 Medium Topic: Misleading Graphs and charts Learning Objective: 02-08 Recognize misleading graphs and charts. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 15) Beginning the vertical scale of a graph at a value different from zero can cause increases to look more dramatic. Answer: TRUE Explanation: This can cause extreme interpretations at first; it is always important to note on your graph what value you are beginning with on your graph. Difficulty: 2 Medium Topic: Misleading Graphs and charts Learning Objective: 02-08 Recognize misleading graphs and charts. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 46 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 16) A runs plot is a form of scatter plot. Answer: TRUE Explanation: A runs plot is also known as a times series plot. Difficulty: 1 Easy Topic: Scatter Plots Learning Objective: 02-07 Examine the relationships between variables by using scatter plots. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 17) The stem-and-leaf display is advantageous because it allows us to actually see the measurements in the data set. Answer: TRUE Explanation: It visually displays all of the data points that were collected for an analysis. Difficulty: 1 Easy Topic: Stem-and-Leaf Displays Learning Objective: 02-05 Construct and interpret stem-and-leaf displays. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 18) Splitting the stems refers to assigning the same stem to two or more rows of the stem-andleaf display. Answer: TRUE Explanation: This is another way of stretching the display of the data. Difficulty: 2 Medium Topic: Stem-and-Leaf Displays Learning Objective: 02-05 Construct and interpret stem-and-leaf displays. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 19) When data are qualitative, the bars should never be separated by gaps. Answer: FALSE Explanation: Bar graphs for qualitative data are displayed with a gap between each category. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 47 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 20) Each stem of a stem-and-leaf display should be a single digit. Answer: FALSE Explanation: Leaves on the stem-and-leaf are a single digit. Difficulty: 2 Medium Topic: Stem-and-Leaf Displays Learning Objective: 02-05 Construct and interpret stem-and-leaf displays. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 21) Leaves on a stem-and-leaf display should be rearranged so that they are in increasing order from left to right. Answer: TRUE Explanation: This helps keeps order and aids in helping the reader to visually see all of the data. Difficulty: 2 Medium Topic: Stem-and-Leaf Displays Learning Objective: 02-05 Construct and interpret stem-and-leaf displays. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 22) Gauges feature a single measure showing variation over time. Answer: FALSE Explanation: Sparklines feature a single measure showing variation over time. Difficulty: 2 Medium Topic: Graphical Descriptive Analytics Learning Objective: 02-09 Construct and interpret gauges, bullet graphs, treemaps, and sparklines. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 23) Data drill down is a form of data discovery. Answer: TRUE Explanation: Data drill down reveals more detailed data that underlie a higher-level summary. Difficulty: 1 Easy Topic: Graphical Descriptive Analytics Learning Objective: 02-09 Construct and interpret gauges, bullet graphs, treemaps, and sparklines. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 48 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 24) Treemaps are used to compare multiple stem-and-leaf diagrams. Answer: FALSE Explanation: Treemaps help visualize two (or more) variables in a series of clustered rectangles. Difficulty: 2 Medium Topic: Graphical Descriptive Analytics Learning Objective: 02-09 Construct and interpret gauges, bullet graphs, treemaps, and sparklines. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 25) Sparklines always need to be displayed with either their axes or coordinates. Answer: FALSE Explanation: Sparklines seldom show their axes or coordinates. Difficulty: 2 Medium Topic: Graphical Descriptive Analytics Learning Objective: 02-09 Construct and interpret gauges, bullet graphs, treemaps, and sparklines. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 26) A bullet graph features a single measure and displays it as either a horizontal or vertical bar. Answer: TRUE Explanation: These ranges of the single measure represent qualitative measures of performance and can be displayed as different colors of varying intensities. Difficulty: 1 Easy Topic: Graphical Descriptive Analytics Learning Objective: 02-09 Construct and interpret gauges, bullet graphs, treemaps, and sparklines. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 49 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 27) Key performance indicators are best represented by a data discovery method. Answer: FALSE Explanation: KPIs are best represented by an analytic dashboard. Difficulty: 3 Hard Topic: Graphical Descriptive Analytics Learning Objective: 02-09 Construct and interpret gauges, bullet graphs, treemaps, and sparklines. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 28) A treemap displays information as a series of clustered rectangles. Answer: TRUE Explanation: This large rectangle in the treemap can be broken into smaller rectangles to represent major segments. Difficulty: 1 Easy Topic: Graphical Descriptive Analytics Learning Objective: 02-09 Construct and interpret gauges, bullet graphs, treemaps, and sparklines. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 29) Sparklines are line charts and are often embedded with the text where they are being discussed. Answer: TRUE Explanation: Sparklines represent the general shape of the variation in some measurement such as temperature or price. Difficulty: 2 Medium Topic: Graphical Descriptive Analytics Learning Objective: 02-09 Construct and interpret gauges, bullet graphs, treemaps, and sparklines. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 50 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 30) An analytic dashboard presents both current and historical trends of a business's key performance indicators. Answer: TRUE Explanation: This allows the reader to monitor the key functions in a particular business. Difficulty: 2 Medium Topic: Graphical Descriptive Analytics Learning Objective: 02-09 Construct and interpret gauges, bullet graphs, treemaps, and sparklines. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 31) If space is an issue when presenting analytic dashboard graphics, gauges should be used most frequently. Answer: FALSE Explanation: Gauges take up considerable space and are cluttered. Difficulty: 3 Hard Topic: Graphical Descriptive Analytics Learning Objective: 02-09 Construct and interpret gauges, bullet graphs, treemaps, and sparklines. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 32) Which of the following is not a graphical tool for descriptive analytics (dashboards)? A) bullet graph B) sparkline C) raw data D) treemap E) gauge Answer: C Explanation: Raw data is data that has not been processed; no graphical tools have been applied to it yet. Difficulty: 1 Easy Topic: Graphical Descriptive Analytics Learning Objective: 02-09 Construct and interpret gauges, bullet graphs, treemaps, and sparklines. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 51 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 33) A(n) ________ is a graphical presentation of the current status and historical trends of a business's key performance indicators. A) frequency distribution B) histogram C) Pareto chart D) dashboard Answer: D Explanation: A dashboard analysis allows you to monitor all of the key functions of a business. Difficulty: 2 Medium Topic: Graphical Descriptive Analytics Learning Objective: 02-09 Construct and interpret gauges, bullet graphs, treemaps, and sparklines. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 34) As a business owner, I have requested my staff to develop a set of dashboards that can be used by the public to show wait time at each of my four local coffee shops at peak times during the day and whether the time is short, medium, or long. Which of the following graphical displays would be the best choice? A) bullet graph B) sparkline C) treemap D) gauges Answer: A Explanation: A bullet graph is used when you are analyzing a single measure—in this case wait time. Difficulty: 3 Hard Topic: Graphical Descriptive Analytics Learning Objective: 02-09 Construct and interpret gauges, bullet graphs, treemaps, and sparklines. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 52 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 35) Which of the following is the best analytic dashboard graphical method for visualizing hierarchical information? A) bullet graph B) sparkline C) treemap D) gauge Answer: C Explanation: A treemap is used when visualizing hierarchical information because the information is displayed as a tree where different branchings would be used to show the hierarchical information. Difficulty: 2 Medium Topic: Graphical Descriptive Analytics Learning Objective: 02-09 Construct and interpret gauges, bullet graphs, treemaps, and sparklines. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 36) Which of the following tools used by graphical descriptive analytics will show variation over time? A) bullet graph B) sparkline C) treemap D) gauge Answer: B Explanation: A sparkline is a line chart that presents the general shape of the variation in some particular measures like temperature or price. Difficulty: 2 Medium Topic: Graphical Descriptive Analytics Learning Objective: 02-09 Construct and interpret gauges, bullet graphs, treemaps, and sparklines. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 53 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 37) A(n) ________ is a graph of a cumulative distribution. A) histogram B) scatter plot C) ogive D) pie chart Answer: C Explanation: An ogive is a graph of the cumulative frequency of the class or the cumulative relative frequencies or the cumulative percent frequencies. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 38) ________ can be used to study the relationship between two variables. A) Cross-tabulation tables B) Frequency tables C) Cumulative frequency distributions D) Dot plots Answer: A Explanation: Frequency distributions and dot plots only use one variable. To study the relationship between two variables, you need to use either cross-tabulation tables or scatter plots. Difficulty: 1 Easy Topic: Contingency Tables Learning Objective: 02-06 Examine the relationships between variables by using contingency tables. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 54 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 39) Row or column percentages can be found in A) frequency tables. B) relative frequency tables. C) cross-tabulation tables. D) cumulative frequency tables. Answer: C Explanation: Cross-tabulation tables show the relationship between two variables using rows and column percentages. Difficulty: 2 Medium Topic: Contingency Tables Learning Objective: 02-06 Examine the relationships between variables by using contingency tables. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 40) All of the following are used to describe quantitative data except the ________. A) histogram B) stem-and-leaf chart C) dot plot D) pie chart Answer: D Explanation: Pie charts are used only for categorical or qualitative data. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 55 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 41) An unusually large or small observation separated from the rest of the data is a(n) ________. A) absolute extreme B) outlier C) mode D) quartile Answer: B Explanation: Outliers are identified as measurements that are widely separated from the other data measurements. Difficulty: 1 Easy Topic: Stem-and-Leaf Displays; Dot Plots Learning Objective: 02-05 Construct and interpret stem-and-leaf displays.; 02-04 Construct and interpret dot plots. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 42) Which of the following graphs is for qualitative data? A) histogram B) bar chart C) ogive plot D) stem-and-leaf Answer: B Explanation: Histogram, stem-and-leaf, and frequency (ogive) graphs display quantitative data. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 56 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 43) A plot that allows us to visualize the relationship between two variables is a(n) ________ plot. A) frequency B) scatter C) dot D) ogive Answer: B Explanation: Scatter plots display the relationship between two variables. Difficulty: 2 Medium Topic: Scatter Plots Learning Objective: 02-07 Examine the relationships between variables by using scatter plots. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 44) A stem-and-leaf display is best used to ________. A) provide a point estimate of the variability of the data set B) provide a point estimate of the central tendency of the data set C) display the shape of the distribution D) display a two-variable treemap Answer: C Explanation: It is more difficult to find central tendency and variability using a stem-and-leaf display. It is easy to visualize the shape of the distribution using stem-and-leaf. Difficulty: 2 Medium Topic: Stem-and-Leaf Displays Learning Objective: 02-05 Construct and interpret stem-and-leaf displays. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 57 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 45) Which of the following divides quantitative measurements into classes and graphs the frequency, relative frequency, or percentage frequency for each class? A) histogram B) dot plot C) stem-and-leaf display D) scatter plot Answer: A Explanation: A box plot does not easily group measurements into classes; a scatter plot is for looking at the relationship between two variables. Difficulty: 3 Hard Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 46) A ________ displays the frequency of each class with qualitative data and a ________ displays the frequency of each class with quantitative data. A) histogram; stem-and-leaf display B) bar chart; histogram C) scatter plot; bar chart D) stem-and-leaf; pie chart Answer: B Explanation: The histogram and stem-and-leaf are used to graphically display quantitative data; a scatter plot is used for displaying the relationship between two variables. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data; Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives.; 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 58 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 47) A ________ shows the relationship between two variables. A) stem-and-leaf B) bar chart C) histogram D) scatter plot E) pie chart Answer: D Explanation: Pie charts and bar charts are used for a single qualitative variable; stem-and-leaf charts and histograms are used for displaying a single quantitative variable. Difficulty: 2 Medium Topic: Scatter Plots Learning Objective: 02-07 Examine the relationships between variables by using scatter plots. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 48) A(n) ________ can be used to differentiate the "vital few" causes of quality problems from the "trivial many" causes of quality problems. A) histogram B) scatter plot C) pareto chart D) ogive plot E) stem-and-leaf display Answer: C Explanation: A pareto chart is a specialized bar chart to look at the frequency of categories; a scatter plot is for displaying the relationship between two variables; a histogram, stem-and-leaf, and ogive plot are used to display quantitative data. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-02 Construct and interpret Pareto charts. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 59 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 49) ________ and ________ are used to describe qualitative (categorical) data. A) Stem-and-leaf displays; scatter plots B) Scatter plots; histograms C) Dot plots; bar charts D) Bar charts; pie charts E) Pie charts; histograms Answer: D Explanation: Stem-and-leaf displays, box plots, and histograms are used for quantitative data; scatter plots are for displaying the relationship between two variables. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 50) Which one of the following graphical tools is used with quantitative data? A) bar chart B) histogram C) pie chart D) Pareto chart Answer: B Explanation: Pie charts, Pareto charts, and bar charts are used with categorical/qualitative data. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 60 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 51) When developing a frequency distribution, the class (group) intervals must be ________. A) large B) small C) integer D) nonoverlapping E) equal Answer: D Explanation: There is no definitive size of intervals for classes, and intervals can be fractional. The number of classes can result in the final class having a different interval size than the previous ones. Difficulty: 3 Hard Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 52) Which of the following graphical tools is not used to study the shapes of distributions? A) stem-and-leaf display B) scatter plot C) histogram D) dot plot Answer: B Explanation: Scatter plots are used to display the relationship between two variables. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 61 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 53) All of the following are used to describe qualitative data except the ________. A) bar chart B) pie chart C) histogram D) Pareto chart Answer: C Explanation: Histograms are used for quantitative data. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 54) If there are 130 values in a data set, how many classes should be created for a frequency histogram? A) 4 B) 5 C) 6 D) 7 E) 8 Answer: E Explanation: 2k, where k = number of classes and 2k is the closest value larger than 130. 27 = 128; 28 = 256. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 62 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 55) If there are 120 values in a data set, how many classes should be created for a frequency histogram? A) 4 B) 5 C) 6 D) 7 E) 8 Answer: D Explanation: 2k, where k = number of classes and 2k is the closest value larger than 120. 27 = 128. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 56) If there are 62 values in a data set, how many classes should be created for a frequency histogram? A) 4 B) 5 C) 6 D) 7 E) 8 Answer: C Explanation: 2k, where k = number of classes and 2k is the closest value larger than 62. 26 = 64. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 63 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 57) If there are 30 values in a data set, how many classes should be created for a frequency histogram? A) 4 B) 5 C) 6 D) 7 E) 8 Answer: B Explanation: 2k, where k = number of classes and 2k is the closest value larger than 30. 25 = 32. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 64 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 58) A CFO is looking at what percentage of a company's resources are spent on computing. He samples companies in the pharmaceutical industry and develops the following stem-and-leaf display (leaf unit = 0.1). 5 6 7 8 9 10 11 12 13 269 255568999 11224557789 001222458 02455679 1556 137 255 What is the approximate shape of the distribution of the data? A) normal B) skewed to the right C) skewed to the left D) bimodal E) uniform Answer: B Explanation: With outliers at the stem of 13 and the majority of the data grouped around stems 6, 7, and 8, the shape is skewed with the outliers to the right. Difficulty: 2 Medium Topic: Stem-and-Leaf Displays Learning Objective: 02-05 Construct and interpret stem-and-leaf displays. Bloom's: Analyze AACSB: Analytical Thinking Accessibility: Keyboard Navigation 65 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 59) A CFO is looking at what percentage of a company's resources are spent on computing. He samples companies in the pharmaceutical industry and develops the following stem-and-leaf display (leaf unit = 0.1). 5 6 7 8 9 10 11 12 13 269 255568999 11224557789 001222458 02455679 1556 137 255 What is the smallest percentage spent on R&D? A) 5.9 B) 5.6 C) 5.2 D) 5.02 E) 50.2 Answer: C Explanation: The smallest value displayed in the graph is 5.2 percent. Difficulty: 2 Medium Topic: Stem-and-Leaf Displays Learning Objective: 02-05 Construct and interpret stem-and-leaf displays. Bloom's: Apply AACSB: Reflective Thinking Accessibility: Keyboard Navigation 66 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 60) A CFO is looking at what percentage of a company's resources are spent on computing. He samples companies in the pharmaceutical industry and develops the following stem-and-leaf display (leaf unit = 0.1). 5 6 7 8 9 10 11 12 13 269 255568999 11224557789 001222458 02455679 1556 137 255 If you were creating a frequency histogram using these data, how many classes would you create? A) 4 B) 5 C) 6 D) 7 E) 8 Answer: C Explanation: There are 50 data measurements. 2k, where k = number of classes and 2k is the closest value larger than 50. 26 = 64. Difficulty: 2 Medium Topic: Stem-and-Leaf Displays; Graphically Summarizing Quantitative Data Learning Objective: 02-05 Construct and interpret stem-and-leaf displays.; 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 67 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 61) A CFO is looking at what percentage of a company's resources are spent on computing. He samples companies in the pharmaceutical industry and develops the following stem-and-leaf display (leaf unit = 0.1). 5 6 7 8 9 10 11 12 13 269 255568999 11224557789 001222458 02455679 1556 137 255 What would be the class length used in creating a frequency histogram? A) 1.4 B) 8.3 C) 1.2 D) 1.7 E) 0.9 Answer: A Explanation: There are 50 data measurements. 2k, where k = number of classes and 2k is the closest value larger than 50. 26 = 64, so 6 classes. Class length = (Max value − Min value)/6 = (13.5 − 5.2)/6. Length = 1.38, rounded to 1.4. Difficulty: 2 Medium Topic: Stem-and-Leaf Displays; Graphically Summarizing Quantitative Data Learning Objective: 02-05 Construct and interpret stem-and-leaf displays.; 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 68 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 62) A CFO is looking at what percentage of a company's resources are spent on computing. He samples companies in the pharmaceutical industry and develops the following stem-and-leaf display (leaf unit = 0.1). 5 6 7 8 9 10 11 12 13 269 255568999 11224557789 001222458 02455679 1556 137 255 What would be the first class interval for the frequency histogram? A) 5.2 < 6.6 B) 5.2 < 6.0 C) 5.0 < 6.0 D) 5.0 < 6.4 E) 5.2 < 6.4 Answer: A Explanation: There are 50 data measurements. 2k, where k = number of classes and 2k is the closest value larger than 50. 26 = 64, so 6 classes. Class length = (Max value − Min value)/6 = (13.5 − 5.2)/6. Length = 1.38, rounded to 1.4. The boundary for the first nonoverlapping interval is the smallest measurement and the sum of the first measurement and the length (5.2 + 1.38 = 6.58). So the first interval will contain the values 5.2 − 6.5. Difficulty: 2 Medium Topic: Stem-and-Leaf Displays; Graphically Summarizing Quantitative Data Learning Objective: 02-05 Construct and interpret stem-and-leaf displays.; 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 69 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 63) A company's Chief Operating Officer (COO) keeps track of the mileage on her trips from her office at corporate headquarters to the company's off-site manufacturing facility and its nearby suppliers. The stem-and-leaf display of the data for one year is below. 76 77 78 79 80 81 82 83 9 114 07 88 2 1 88 How many trips were used in this display? A) 7 B) 9 C) 10 D) 11 E) 12 Answer: E Explanation: Count of measurements is 12. Difficulty: 2 Medium Topic: Stem-and-Leaf Displays Learning Objective: 02-05 Construct and interpret stem-and-leaf displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 70 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 64) A company's Chief Operating Officer (COO) keeps track of the mileage on her trips from her office at corporate headquarters to the company's off-site manufacturing facility and its nearby suppliers. The stem-and-leaf display of the data for one year is below. 76 77 78 79 80 81 82 83 9 114 07 88 2 1 88 In developing a histogram of these data, how many classes would be used? A) 4 B) 5 C) 6 D) 7 E) 8 Answer: A Explanation: Number of measurements = 12; 24 = 16; classes = 4. Difficulty: 2 Medium Topic: Stem-and-Leaf Displays; Graphically Summarizing Quantitative Data Learning Objective: 02-05 Construct and interpret stem-and-leaf displays.; 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 71 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 65) A company's Chief Operating Officer (COO) keeps track of the mileage on her trips from her office at corporate headquarters to the company's off-site manufacturing facility and its nearby suppliers. The stem-and-leaf display of the data for one year is below. 76 77 78 79 80 81 82 83 9 114 07 88 2 1 88 What would be the class length for creating the frequency histogram? A) 14 B) 9 C) 27 D) 18 E) 23 Answer: D Explanation: Measurements = 12; classes = 4; class length = (838 − 769)/4 = 17.25, rounded to 18 Difficulty: 2 Medium Topic: Stem-and-Leaf Displays; Graphically Summarizing Quantitative Data Learning Objective: 02-05 Construct and interpret stem-and-leaf displays.; 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 72 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 66) A company collected the ages from a random sample of its middle managers, with the resulting frequency distribution shown below. Class Interval 20 to < 25 25 to < 30 30 to < 35 35 to < 40 40 to < 45 45 to < 50 Frequency 8 6 5 12 15 7 What would be the approximate shape of the relative frequency histogram? A) symmetrical B) uniform C) linear D) skewed to the left E) skewed to the right Answer: D Explanation: The majority of data lie to the right side of the distribution; the tail of the smaller number of measurements extends to the left, so the graph is skewed with a tail to the left. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 73 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 67) A company collected the ages from a random sample of its middle managers, with the resulting frequency distribution shown below. Class Interval 20 to < 25 25 to < 30 30 to < 35 35 to < 40 40 to < 45 45 to < 50 Frequency 8 6 5 12 15 7 What is the relative frequency for the class with the greatest frequency? A) .132 B) .226 C) .231 D) .283 E) .288 Answer: D Explanation: Measurements = 53; largest interval has 15 measurements.15/53 = .283. Difficulty: 3 Hard Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 74 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 68) A company collected the ages from a random sample of its middle managers, with the resulting frequency distribution shown below. Class Interval 20 to < 25 25 to < 30 30 to < 35 35 to < 40 40 to < 45 45 to < 50 Frequency 8 6 5 12 15 7 What is the midpoint of the third class interval? A) 22.5 B) 27.5 C) 32.5 D) 37.5 E) 42.5 Answer: C Explanation: The midpoint is calculated as halfway between the boundaries of the class. The third class interval is 30 to 35, which yields a midpoint of 32.5. Difficulty: 3 Hard Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 75 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 69) The general term for a graphical display of categorical data made up of vertical or horizontal bars is called a(n) ________. A) pie chart B) Pareto chart C) bar chart D) ogive plot Answer: C Explanation: An ogive plot is based on quantitative data, a Pareto chart is a specialized bar chart, and a pie chart is a circular graphical display. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 70) Pareto charts are frequently used to identify ________. A) random data B) the most common types of defects C) outliers that do not show up on a dot plot D) the cause for extreme skewness to the right Answer: B Explanation: By definition, a defect is a flaw in a population or sample element. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-02 Construct and interpret Pareto charts. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 76 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 71) A graphical portrayal of a quantitative data set that divides the data into classes and gives the frequency of each class is a(n) ________. A) ogive plot B) dot plot C) histogram D) Pareto chart E) bar chart Answer: C Explanation: Pareto and bar charts are used for qualitative data, a dot plot displays individual data points, and an ogive plot is a curved display of the cumulative distribution of the data. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 72) The number of measurements falling within a class interval is called the ________. A) frequency B) relative frequency C) leaf D) cumulative sum Answer: A Explanation: By definition, frequency is the number of measurements. Relative frequency is proportional. A leaf is not a count but part of a graphical display, and the cumulative sum is not a count. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 77 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 73) A relative frequency histogram having a longer tail to the right than to the left is said to be ________. A) skewed to the left B) normal C) a scatter plot D) skewed to the right Answer: D Explanation: A scatter plot is a graphical display of the relationship between two variables; a normal curve is bell-shaped with even distribution on both sides of the high point of the curve. The long tail direction defines the skewness of the graph, in this case skewed to the right. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 74) The proportion of measurements in a class is called the ________ of that class. A) frequency B) relative frequency C) leaf D) cumulative percentage Answer: B Explanation: By definition, frequency is the number of measurements. Relative frequency is proportional. A leaf and the cumulative sum are not counts of measurements or percentages. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 78 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 75) A histogram that has a longer tail extending toward larger values is ________. A) skewed to the left B) normal C) a scatter plot D) skewed to the right Answer: D Explanation: Larger values are to the right of the center part of the graph, resulting in a tail to the right. Thus, the graph is skewed to the right. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 76) A histogram that has a longer tail extending toward smaller values is ________. A) skewed to the left B) normal C) a scatter plot D) skewed to the right Answer: A Explanation: Smaller values are to the left of the center part of the graph, resulting in a tail to the left. Thus, the graph is skewed to the left. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 79 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 77) A type of very simple graph that can be used to summarize a quantitative data set is a(n) ________. A) runs plot B) ogive plot C) dot plot D) pie chart Answer: C Explanation: A runs plot is used for time series data; a pie chart is used for qualitative data; an ogive plot is a specialized graph of the cumulative distribution of data measurements. A dot plot is a simple graphical display of data measurements. Difficulty: 2 Medium Topic: Dot Plots Learning Objective: 02-04 Construct and interpret dot plots. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 78) An example of manipulating a graphical display to distort reality is ________. A) starting the axes at zero B) making the bars in a histogram equal widths C) stretching the axes D) adding an unbiased caption Answer: C Explanation: Starting the axes at zero is the appropriate method of graphical display, as is making the bars in a histogram equal widths. Difficulty: 2 Medium Topic: Misleading Graphs and charts Learning Objective: 02-08 Recognize misleading graphs and charts. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 80 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 79) As a general rule, when creating a stem-and-leaf display, there should be ________ stem values. A) between 3 and 10 B) between 1 and 100 C) no fewer than 20 D) between 5 and 20 Answer: D Explanation: By definition, there should be between 5 and 20 stems to enable a reasonable display of the shape of the distribution. Difficulty: 2 Medium Topic: Stem-and-Leaf Displays Learning Objective: 02-05 Construct and interpret stem-and-leaf displays. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 81 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 80) At the end of their final exam, 550 students answered an additional question in which they rated their instructor's teaching effectiveness, with the following results. Student's Rating of Instructor Very or Somewhat Student's Final Grade Effective A 190 B 75 C 20 D 9 F 1 Very or Somewhat Ineffective 85 120 17 18 15 What proportion of the students who rated their instructor as very or somewhat effective received a B or better in the class? A) 0.345 B) 0.254 C) 0.482 D) 0.898 E) 0.644 Answer: D Explanation: 295 students rated their instructor as very or somewhat effective; (75 + 190) = 265 had a B or better; 265/295 = .898. Difficulty: 3 Hard Topic: Contingency Tables Learning Objective: 02-06 Examine the relationships between variables by using contingency tables. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 82 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 81) At the end of their final exam, 550 students answered an additional question in which they rated their instructor's teaching effectiveness, with the following results. Student's Rating of Instructor Very or Somewhat Student's Final Grade Effective A 190 B 75 C 20 D 9 F 1 Very or Somewhat Ineffective 85 120 17 18 15 What proportion of the students who rated their instructor as very or somewhat effective received a C or lower in the class? A) 0.03 B) 0.06 C) 0.10 D) 0.13 E) 0.15 Answer: C Explanation: 295 received a C or lower in the class; 30/295 = 0.10. Difficulty: 3 Hard Topic: Contingency Tables Learning Objective: 02-06 Examine the relationships between variables by using contingency tables. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 83 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 82) 822 recently purchased books were randomly selected from all recent book purchases over the Internet. The chart below shows the breakdown of the classification of the book type. What percentage of the books in the sample were either mystery or science fiction/fantasy? A) 18.61 B) 36.50 C) 17.88 D) 24.33 E) 22.99 Answer: B Explanation: 300 mystery or science fiction/fantasy books purchased; 300/822 = 36.5%. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 84 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 83) 822 recently purchased books were randomly selected from all recent book purchases over the Internet. The chart below shows the breakdown of the classification of the book type. What percentage of the books in the sample were self-help books? A) 11.44 B) .1144 C) 1.82 D) 0.0182 E) 0.940 Answer: A Explanation: 94/822 = 11.44% Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 85 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 84) 822 recently purchased books were randomly selected from all recent book purchases over the Internet. The chart below shows the breakdown of the classification of the book type. What percentage of the books in the sample were in the top two categories? A) 22.99 B) 20.44 C) 4.50 D) 43.43 E) 0.4343 Answer: D Explanation: 189 + 168 = 357 in the top two categories; 357/822 = 43.43% of the total purchased. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 86 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 85) Using the following data, describe the shape of the data distribution. 1. 2. 3. 4. 5. 11.5 13.5 12.5 15.2 14.7 6. 7. 8. 9. 10. 13.7 14.0 12.0 12.7 12.5 11. 12. 13. 14. 15. 11.0 13.0 16.7 12.5 11.5 16. 17. 18. 19. 20. 14.5 15.5 13.0 18.2 11.7 A) skewed to the left B) bimodal C) normal D) skewed to the right Answer: D Explanation: Create a stem-and-leaf graph. The stem would be 11,12,13,14,15,16,17,18; leaves would be the tenth on each data measurement: The graphical display shows that it is skewed to the right. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 87 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 86) Using the following data, what would be the range of the values of the stem in a stem-andleaf display? 1. 2. 3. 4. 5. 11.5 13.5 12.5 15.2 14.7 6. 7. 8. 9. 10. 13.7 14.0 12.0 12.7 12.5 11. 12. 13. 14. 15. 11.0 13.0 16.7 12.5 11.5 16. 17. 18. 19. 20. 14.5 15.5 13.0 18.2 11.7 A) 11-17 B) 11-18 C) 10-18 D) 12-17 E) 12-18 Answer: B Explanation: Create a stem-and-leaf graph. The stem would be 11,12,13,14,15,16,17,18; leaves would be the tenth on each data measurement: Difficulty: 2 Medium Topic: Stem-and-Leaf Displays Learning Objective: 02-05 Construct and interpret stem-and-leaf displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 88 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 87) Using the following data, what would be the leaf unit in a stem-and-leaf display? 1. 2. 3. 4. 5. 11.5 13.5 12.5 15.2 14.7 6. 7. 8. 9. 10. 13.7 14.0 12.0 12.7 12.5 11. 12. 13. 14. 15. 11.0 13.0 16.7 12.5 11.5 16. 17. 18. 19. 20. 14.5 15.5 13.0 18.2 11.7 A) 1.0 B) 10 C) .10 D) .01 E) .20 Answer: C Explanation: Create a stem-and-leaf graph. The stem would be 11,12,13,14,15,16,17,18; leaves would be the tenth on each data measurement. Difficulty: 2 Medium Topic: Stem-and-Leaf Displays Learning Objective: 02-05 Construct and interpret stem-and-leaf displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 89 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 88) Consider the following data on distances traveled by people to visit the local amusement park and calculate the relative frequency for the shortest distance. Distance 1-8 miles 9-16 miles 17-24 miles 25-32 miles 33-40 miles Frequency 15 12 7 5 1 A) .375 B) .150 C) .500 D) .300 E) .333 Answer: A Explanation: Total of 40 measurements: 15/40 = .375. Difficulty: 1 Easy Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 90 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 89) Consider the following data on distances traveled by people to visit the local amusement park and calculate the relative frequency for the distances over 24 miles. Distance 1-8 miles 9-16 miles 17-24 miles 25-32 miles 33-40 miles Frequency 15 12 7 5 1 A) .375 B) .150 C) .125 D) .025 E) .325 Answer: B Explanation: (5 + 1) = 6 over 24 miles; 6/40 = .15. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 91 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 90) The following is a partial relative frequency distribution of grades in an introductory statistics course. Grade A B C D F Relative Frequency 0.22 ? 0.18 0.17 0.06 Find the relative frequency for the B grade. A) .78 B) .27 C) .65 D) .37 E) .47 Answer: D Explanation: 1.00 − (.22 + .18 + .17 + .06) = 1.00 − .63 = .37 Difficulty: 1 Easy Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 92 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 91) The following is a relative frequency distribution of grades in an introductory statistics course. Grade A B C D F Relative Frequency 0.22 ? 0.18 0.17 0.06 If this was the distribution of 200 students, find the frequency for the highest two grades. A) 44 B) 118 C) 59 D) 74 E) 35 Answer: B Explanation: (.22 + .37) = .59. 59% of 200 = 118. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 93 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 92) The following is a relative frequency distribution of grades in an introductory statistics course. Grade A B C D F Relative Frequency 0.22 ? 0.18 0.17 0.06 If this was the distribution of 200 students, find the frequency of failures. A) 12 B) 6 C) 23 D) 46 E) 3 Answer: A Explanation: The frequency is .06. The frequency of failures is 6% of 200 = 12. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 94 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 93) The following is a relative frequency distribution of grades in an introductory statistics course. Grade A B C D F Relative Frequency 0.22 ? 0.18 0.17 0.06 If we wish to depict these data using a pie chart, find how many degrees should be assigned to the highest grade of A. A) 61.1 B) 22.0 C) 79.2 D) 90.0 E) 212.40 Answer: C Explanation: A's are 22% of total; 360° in a circle: 22% of 360 = 79.2°. Difficulty: 3 Hard Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 95 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 94) Recently an advertising company called 200 people and asked them to identify the company that was in an ad running nationwide. The following results were obtained. Correctly recalled the company Incorrectly recalled the company Total Female 66 44 110 Male 50 40 90 Total 116 84 200 What percentage of those surveyed were female and could not recall the company? A) 40.0 B) 22.0 C) 52.4 D) 66.7 E) 37.9 Answer: B Explanation: Out of 200 people, 44 were female and could not recall the company; 44/200 = 22%. Difficulty: 2 Medium Topic: Contingency Tables Learning Objective: 02-06 Examine the relationships between variables by using contingency tables. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 96 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 95) Recently an advertising company called 200 people and asked them to identify the company that was in an ad running nationwide. The following results were obtained. Correctly recalled the company Incorrectly recalled the company Total Female 66 44 110 Male 50 40 90 Total 116 84 200 What percentage of those surveyed could not correctly recall the company? A) 58.00 B) 56.89 C) 55.00 D) 43.10 E) 42.00 Answer: E Explanation: 84 of 200 could not recall the company; 84/200 = 42%. Difficulty: 2 Medium Topic: Contingency Tables Learning Objective: 02-06 Examine the relationships between variables by using contingency tables. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 97 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 96) A local electronics retailer recently conducted a study on purchasers of large screen televisions. The study recorded the type of television and the credit account balance of the customer at the time of purchase. They obtained the following results. Credit Balance Under $200 $200 − $800 Over $800 Total LED 10 8 16 34 LCD 16 12 12 40 Plasma 40 24 16 80 Projection 5 15 30 50 What percentage of purchases were plasma televisions by customers with the smallest credit balances? A) 50.0 B) 39.2 C) 56.3 D) 34.8 E) 19.6 Answer: E Explanation: 40 of 204 total purchases; 40/204 = 19.6% Difficulty: 2 Medium Topic: Contingency Tables Learning Objective: 02-06 Examine the relationships between variables by using contingency tables. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 98 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 97) A local electronics retailer recently conducted a study on purchasers of large screen televisions. The study recorded the type of television and the credit account balance of the customer at the time of purchase. They obtained the following results. Credit Balance Under $200 $200 − $800 Over $800 Total LED 10 8 16 34 LCD 16 12 12 40 Plasma 40 24 16 80 Projection 5 15 30 50 What percentage of the customers had the highest credit balances and purchased an LCD television? A) 36.3 B) 5.9 C) 19.6 D) 56.3 E) 16.2 Answer: B Explanation: 12 out of 204 = 5.9%. Difficulty: 2 Medium Topic: Contingency Tables Learning Objective: 02-06 Examine the relationships between variables by using contingency tables. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 99 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 98) The number of weekly sales calls by a sample of 25 pharmaceutical salespersons is below. 24, 56, 43, 35, 37, 27, 29, 44, 34, 28, 33, 28, 46, 31, 38, 41, 48, 38, 27, 29, 37, 33, 31, 40, 50 How many classes should be used in the construction of a histogram? A) 4 B) 6 C) 10 D) 5 E) 2 Answer: D Explanation: Classes are determined by the value of k, where 2k yields a value that is closest to the sample size and is also larger than the sample size. k = 5, so 25 = 32. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 100 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 99) The number of weekly sales calls by a sample of 25 pharmaceutical salespersons is below. 24, 56, 43, 35, 37, 27, 29, 44, 34, 28, 33, 28, 46, 31, 38, 41, 48, 38, 27, 29, 37, 33, 31, 40, 50 What is the shape of the distribution of the data? A) skewed to the right B) skewed to the left C) normal D) bimodal Answer: A Explanation: Create a frequency table that can be used to observe the shape of the distribution. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 101 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 100) The number of items rejected daily by a manufacturer because of defects for the last 30 days are: 20, 21, 8, 17, 22, 19, 18, 19, 14, 17, 11, 6, 21, 25, 4, 19, 9, 12, 16, 16, 10, 28, 24, 6, 21, 20, 25, 5, 17, 8 How many classes should be used in constructing a histogram? A) 6 B) 5 C) 7 D) 4 E) 8 Answer: B Explanation: Number of classes = k, where 2k > 30. So k = 5. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 102 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 101) The number of weekly sales calls by a sample of 25 pharmaceutical salespersons is below. 24, 56, 43, 35, 37, 27, 29, 44, 34, 28, 33, 28, 46, 31, 38, 41, 48, 38, 27, 29, 37, 33, 31, 40, 50 Construct an ogive of the weekly sales calls. Answer: Create a frequency table with cumulative relative frequency and then construct the graph using the cumulative frequency points. Classes Frequency Rel Freq 24 < 31 31 < 38 38 < 45 45 < 52 52 < 57 7 8 6 3 1 0.28 0.32 0.24 0.12 0.04 Cum Rel Freq 0.28 0.60 0.84 0.96 1.00 Difficulty: 3 Hard Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 103 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 102) The number of items rejected daily by a manufacturer because of defects for the last 30 days are: 20, 21, 8, 17, 22, 19, 18, 19, 14, 17, 11, 6, 21, 25, 4, 19, 9, 12, 16, 16, 10, 28, 24, 6, 21, 20, 25, 5, 17, 8 Complete this frequency table for these data. Frequency Rel Freq Cum Freq 4<9 9 < 14 14 < 19 19 < 24 24 < 29 Answer: Classes Frequency Rel Freq 4<9 9 < 14 14 < 19 19 < 24 24 < 29 6 4 7 9 4 0.2 0.133 0.233 0.30 0.133 Cum Rel Freq 0.2 0.333 0.567 0.867 1.00 The Cum Freq column should be .566, .866, and 0.999. The values listed do not add to 1.00 exactly due to rounding. Using the given classes, frequency = number of rejected items in each class, relative frequency = frequency/30, and cumulative frequency = sum of successive class relative frequencies. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 104 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 103) The number of items rejected daily by a manufacturer because of defects for the last 30 days are: 20, 21, 8, 17, 22, 19, 18, 19, 14, 17, 11, 6, 21, 25, 4, 19, 9, 12, 16, 16, 10, 28, 24, 6, 21, 20, 25, 5, 17, 8 Construct a stem-and-leaf display. Answer: One possible stem-and-leaf display (with each stem split into five): Stem 0 0 0 1 1 1 1 1 2 2 2 2 2 Leaf 45 66 889 01 2 4 66777 8999 00111 2 455 8 A second possible stem-and-leaf display (with each stem split into two): Stem 0 0 1 1 2 2 Leaf 4 566889 0124 66777899 0011124 558 Stem should be the 10s unit. Construct by splitting stems, since the range of values is only 5-28 and there should be approximately 10 stems. When splitting the stem, consider the number of values in the split stems. Leaf unit should be the ones unit. Difficulty: 2 Medium Topic: Stem-and-Leaf Displays Learning Objective: 02-05 Construct and interpret stem-and-leaf displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 105 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 104) The number of items rejected daily by a manufacturer because of defects for the last 30 days are: 20, 21, 8, 17, 22, 19, 18, 19, 14, 17, 11, 6, 21, 25, 4, 19, 9, 12, 16, 16, 10, 28, 24, 6, 21, 20, 25, 5, 17, 8 Construct an ogive of the number of items rejected daily. Answer: Construct a frequency table (5 classes) with cumulative relative frequency. Classes Frequency Rel Freq 4<9 9 < 14 14 < 19 19 < 24 24 < 29 6 4 7 9 4 0.20 0.13 0.23 0.30 0.13 Cum Rel Freq 0.20 0.33 0.57 0.87 1.00 Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 106 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 105) Consider the following data. 1. 2. 3. 4. 5. 11.5 13.5 12.5 15.2 14.7 6. 7. 8. 9. 10. 13.7 14.0 12.0 12.7 12.5 11. 12. 13. 14. 15. 11.0 13.0 16.7 12.5 11.5 16. 17. 18. 19. 20. 14.5 15.5 13.0 18.2 11.7 Create a stem-and-leaf display for the sample. Answer: One possible stem-and-leaf display as might be created by Minitab: Stem-and-leaf of given data, N = 20, Leaf Unit = 0.10 4 9 (4) 7 4 2 1 1 11 12 13 14 15 16 17 18 0557 05557 0057 057 25 7 2 Stems should be from 11 to 18; leaves are the tenth unit. Difficulty: 2 Medium Topic: Stem-and-Leaf Displays Learning Objective: 02-05 Construct and interpret stem-and-leaf displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 107 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 106) Consider the following data on distances traveled by people to visit the local amusement park. Distance 1-8 miles 9-16 miles 17-24 miles 25-32 miles 33-40 miles Frequency 15 12 7 5 1 Construct an ogive that corresponds to the frequency table. Answer: Calculate the relative frequency for each class (15/40, 12/40, 7/40, 5/40, 1/40; or .375, .30, .175, .125, and .025) and then the cumulative frequency (.375, .675, .850, .975, 1.00). Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 108 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 107) The following is a relative frequency distribution of grades in an introductory statistics course. Grade A B C D F Relative Frequency 0.22 0.37 0.18 0.17 0.06 If this was the distribution of 200 students, give the frequency distribution for this data. Answer: Grade A B C D F Relative Frequency 44 74 36 34 12 Convert from proportion (relative frequency) to frequency by multiplying each relative frequency by 200 (e.g., .22 × 200 = 44 for grade A). Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 109 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 108) The following is a relative frequency distribution of grades in an introductory statistics course. Grade A B C D F Relative Frequency 0.22 0.37 0.18 0.17 0.06 Construct a percent bar chart for this data. Answer: Each grade category is displayed as a bar on a percent bar chart. Difficulty: 1 Easy Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 110 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 109) The following is a relative frequency distribution of grades in an introductory statistics course. Grade A B C D F Relative Frequency 0.22 0.37 0.18 0.17 0.06 If we wish to depict these data using a pie chart, find how many degrees (out of 360 degrees) should be assigned to each grade. Answer: Grade A B C D F Relative Frequency 79.2 133.2 64.8 61.2 21.6 Each proportion (relative frequency) is considered that portion of a circle's 360 degrees. Multiply the relative frequency (proportion) by 360 to convert to actual circle degrees (e.g., grade A: .22 × 360 = 79.2 degrees). Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 111 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 110) Fill in the missing components of the following frequency distribution constructed for a sample size of 50. Class Frequency ___ < 7.95 ___ < 8.05 8.05 < ___ ___ < 8.25 8.25 < ___ Rel Frequency Cum Rel Freq 0.12 0.48 0.24 0.10 Answer: Class Frequency 7.85 < 7.95 7.95 < 8.05 8.05 < 8.15 8.15 < 8.25 8.25 < 8.35 6 18 12 5 9 Rel Frequency 0.12 0.36 0.24 0.10 0.18 Cum Rel Freq 0.12 0.48 0.72 0.82 1.00 Work each row to generate the missing frequency and/or relative frequency given a sample size of 50. For example, first class: cum rel freq = rel freq = x/50 = 0.12, so x = 6. Complete the class interval by recognizing that the second class beginning boundary is the end of the first interval's boundary and using the class length calculated in the second class (0.10) to apply to all other classes. Difficulty: 3 Hard Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 112 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 111) Recently an advertising company called 200 people and asked them to identify the company that was in an ad running nationwide. They obtained the following results. Correctly recalled the company Incorrectly recalled the company Total Female 66 44 110 Male 50 40 90 Total 116 84 200 Construct a table of row percentages. Answer: Correctly recalled the company Incorrectly recalled the company Female 56.9% 52.4% Male 43.1% 47.6% Total 100.0% 100.0% Row percentages are calculated by dividing each part of the row by the total of the row and multiplying by 100. For example, Female and correctly recalled = 66, which yields a row percentage of (66/116)*100 = 56.9%. Difficulty: 2 Medium Topic: Contingency Tables Learning Objective: 02-06 Examine the relationships between variables by using contingency tables. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 113 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 112) Recently an advertising company called 200 people and asked them to identify the company that was in an ad running nationwide. They obtained the following results. Correctly recalled the company Incorrectly recalled the company Total Female 66 44 110 Male 50 40 90 Total 116 84 200 Construct a table of column percentages. Answer: Correctly recalled the company Incorrectly recalled the company Total Female 60.0% 40.0% 100.0% Male 55.6% 44.4% 100.0% Column percentages are calculated by dividing each part of the column by the total of the column and multiplying by 100. For example, Female and correctly recalled = 66, which yields a column percentage of (66/110)*100 = 60.0%. Difficulty: 2 Medium Topic: Contingency Tables Learning Objective: 02-06 Examine the relationships between variables by using contingency tables. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 114 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 113) A local electronics retailer recently conducted a study on purchasers of large screen televisions. The study recorded the type of television and the credit account balance of the customer at the time of purchase. They obtained the following results. Credit Balance Under $200 $200−$800 Over $800 Total LED 10 S 16 34 LCD 16 12 12 40 Plasma 40 24 16 80 Projection 5 15 30 50 Construct a table of row percentages. Answer: Credit Balance Under $200 $200−$800 Over $800 LED (10/71)*100 = 14.1% (8/59)*100 = 13.6% (16/74)*100 = 21.6% LCD (16/71)*100 = 22.5% (12/59)*100 = 20.3% (12/74)*100 = 16.2% Plasma (40/71)*100 = 56.3% (24/59)*100 = 40.7% (16/74)*100 = 21.6% Projection (5/71)*100 = 7.0% (15/59)*100 = 25.4% (30/74)*100 = 40.5% Total 100.0% 100.0% 100.0% Row percentages are calculated by dividing each part of the row by the total of the row and multiplying by 100. Need to calculate the totals for each row (under $200 = 71; $200-$800 = 59; over $800 = 74). For example, credit balance under $200 and LCD TV = 16, which yields row percentage (16/71)*100 = 22.5%. Difficulty: 2 Medium Topic: Contingency Tables Learning Objective: 02-06 Examine the relationships between variables by using contingency tables. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 115 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 114) A local electronics retailer recently conducted a study on purchasers of large screen televisions. The study recorded the type of television and the credit account balance of the customer at the time of purchase. They obtained the following results. Credit Balance Under $200 $200−$800 Over $800 Total LED 10 S 16 34 LCD 16 12 12 40 Plasma 40 24 16 80 Projection 5 15 30 50 Construct a table of column percentages. Answer: Credit Balance Under $200 $200−$800 Over $800 Total LED 29.4% 23.5% 47.1% 100.0% LCD 40.0% 30.0% 30.0% 100.0% Plasma 50.0% 30.0% 20.0% 100.0% Projection 10.0% 30.0% 60.0% 100.0% Column percentages calculated by dividing each part of the column by the total of the column and multiplying by 100. For example, credit balance under $200 and LCD TV = 16 yields row percentage (16/40)*100 =40.0%. Difficulty: 2 Medium Topic: Contingency Tables Learning Objective: 02-06 Examine the relationships between variables by using contingency tables. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 116 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 115) Math test anxiety can be found throughout the general population. A study of 116 seniors at a local high school was conducted. The following table was produced from the data. Complete the missing parts. Score Range Very anxious 37-50 Anxious/tense 33-36 Some mild anxiety 27-32 Generally relaxed 20-26 Very relaxed 10-19 Frequency 8 Rel Frequency Cum Freq Dist 0.19 0.26 24 0.67 0.33 Answer: Score Range Very anxious 37-50 Anxious/tense 33-36 Some mild anxiety 27-32 Generally relaxed 20-26 Very relaxed 10-19 Frequency 22 8 24 24 38 Rel Frequency 0.19 0.07 0.207 0.207 0.33 Cum Freq Dist 0.19 0.26 0.467 0.674 1.00 Work each row to generate the missing frequency and/or relative frequency given a sample size of 116. For example, first class cum freq = rel freq = x/116 = 0.19, so x = 22. Use the definition of cumulative frequency, which is the sum of the class relative frequency and the previous class cumulative frequency (for example, "generally relaxed" relative frequency = 24/116 = .207, which with a cumulative frequency of .67 gives the previous class of "some mild anxiety" a cumulative frequency of .47). Difficulty: 3 Hard Topic: Graphically Summarizing Qualitative Data; Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives.; 02-01 Summarize qualitative data by using frequency distributions, bar charts, and pie charts. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 117 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 116) The number of weekly sales calls by a sample of 25 pharmaceutical salespersons is below. 24, 56, 43, 35, 37, 27, 29, 44, 34, 28, 33, 28, 46, 31, 38, 41, 48, 38, 27, 29, 37, 33, 31, 40, 50 Construct a histogram. Answer: Construct a frequency table. You can use five to seven classes, depending on your choice and calculation of length as a whole integer. Classes Midpoint 25 30 35 40 45 50 55 Frequency 3 6 6 4 3 2 1 While the frequency table and histogram shown above are technically valid, it is unlikely that a student would create them based on the instructions in the textbook. A more likely frequency table a student might create would be: Class 24 < 31 31 < 38 38 < 45 45 < 52 52 < 59 Frequency 7 8 6 3 1 118 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. A histogram could easily be derived from this frequency table. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 117) The number of weekly sales calls by a sample of 25 pharmaceutical salespersons is below. 24, 56, 43, 35, 37, 27, 29, 44, 34, 28, 33, 28, 46, 31, 38, 41, 48, 38, 27, 29, 37, 33, 31, 40, 50 Construct a stem-and-leaf plot. Answer: One possible stem-and-leaf display as might be created by Minitab: Stem-and-Leaf of Sales Calls N= 25 Leaf Unit = 1.0 1 7 12 (5) 8 4 2 1 2 2 3 3 4 4 5 5 4 778899 11334 57788 0134 68 0 6 Without Minitab, students would be unlikely to create the leftmost column with frequency information. The stem should be split and consist of 20, 30, 40, and 50. Leaves are the single units for the number of sales calls (e.g., 20 stem: leaves = 4, 7, 7, 8, 8, 9, 9). Difficulty: 2 Medium Topic: Stem-and-Leaf Displays Learning Objective: 02-05 Construct and interpret stem-and-leaf displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 119 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 118) The number of weekly sales calls by a sample of 25 pharmaceutical salespersons is below. 24, 56, 43, 35, 37, 27, 29, 44, 34, 28, 33, 28, 46, 31, 38, 41, 48, 38, 27, 29, 37, 33, 31, 40, 50 Construct a frequency polygon. Answer: The frequency polygon is the line connecting the height (frequency) of the midpoint of each class. Construct a frequency table. Classes Midpoint 25 30 35 40 45 50 55 Frequency 3 6 6 4 3 2 1 While the frequency table and frequency polygon shown above are technically valid, it is unlikely that a student would create them based on the instructions in the textbook. A more likely frequency table a student might create would be: Class 24 < 31 31 < 38 38 < 45 45 < 52 52 < 59 Frequency 7 8 6 3 1 A frequency polygon could easily be derived from this frequency table. 120 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Difficulty: 2 Medium Topic: Graphically Summarizing Quantitative Data Learning Objective: 02-03 Summarize quantitative data using frequency distributions, histograms, frequency polygons, and ogives. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 121 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 119) The following table lists the types of customer complaint calls on satellite TV service during the first two months after installation. No signal detected Can't receive local channels Missing channels Intermittent reception Remote control problems Other issues 20% 14% 21% 8% 25% 12% Construct a Pareto chart. Answer: A Pareto chart is a specialization of the bar chart used for categorical variables. The largest percentage value is charted at the far left, and each problem percentage is graphed in decreasing order. When showing "other" issues, always place that bar to the right because it includes an accumulation of various reasons. Difficulty: 2 Medium Topic: Graphically Summarizing Qualitative Data Learning Objective: 02-02 Construct and interpret Pareto charts. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 122 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 120) The following data consist of the number of sick days taken by the 100 employees at a small manufacturing company for the past 18 months. Construct a dot plot of these data and describe the distribution. 5, 1, 4, 8, 0, 6, 3, 5, 3, 4, 7, 15, 5, 8, 2, 1, 5, 4 Answer: Data are skewed to the right with one outlier. A dot plot is constructed as a number line with minimum to maximum values (0 to 15). Individual values are shown along the line as points (dots). With an outlier at the maximum value, the shape has a tail to the right. Difficulty: 2 Medium Topic: Dot Plots Learning Objective: 02-04 Construct and interpret dot plots. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 123 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 1) The median is the measure of central tendency that divides a population or sample into four equal parts. Answer: FALSE Explanation: The median divides a population into two equal parts. Difficulty: 1 Easy Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 2) The population mean is the average of the population measurements. Answer: TRUE Explanation: This mean is calculated by adding all of the population measurements and dividing the resulting sum by the number of population measurements. Difficulty: 2 Medium Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 3) The mode is the measurement in a sample or population that occurs most frequently. Answer: TRUE Explanation: This is the measurement that occurs at the highest frequency. Difficulty: 2 Medium Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 124 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 4) The population mean is the point estimate of the sample mean. Answer: FALSE Explanation: The sample mean is the point estimate of the population mean. Difficulty: 2 Medium Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 5) The median is said to be resistant to extreme values. Answer: TRUE Explanation: This is because the median divides the population or sample into two roughly equal parts. Difficulty: 2 Medium Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 6) The range of the measurement is the largest measurement plus the smallest measurement. Answer: FALSE Explanation: The range is the largest minus the smallest measurement. Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 7) The population variance is the average of the squared deviations of the individual population measurements from the population mean. Answer: TRUE Explanation: This population variance is represented by sigma squared. Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 8) In a symmetric population, the median equals the mode. 125 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. Answer: TRUE Explanation: The population is a perfect bell curve. Difficulty: 2 Medium Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 9) It is appropriate to use the Empirical Rule to describe a population that is extremely skewed. Answer: FALSE Explanation: The Empirical Rule should be used for normally distributed populations. Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-03 Use the Empirical Rule and Chebyshev's Theorem to describe variation. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 10) The median is the value below which and above which approximately 50 percent of the measurements lie. Answer: TRUE Explanation: It is the central tendency of a population and evenly splits the population or sample into two. Difficulty: 1 Easy Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 126 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 11) If there are seven classes in a frequency distribution, then the fourth class will always contain the median. Answer: FALSE Explanation: The median is the middle measurement of the data set. Depending on the shape of the distribution, the median can be in any of the classes. Difficulty: 2 Medium Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Evaluate AACSB: Reflective Thinking Accessibility: Keyboard Navigation 12) Range is a better measure of variation than standard deviation. Answer: FALSE Explanation: The standard deviation is a better measure of variability than range. Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 13) The mean is one component of the five-number summary. Answer: FALSE Explanation: The five-number summary includes Q1, Q2, Q3, and the smallest and largest measurements. Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 127 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 14) The pth percentile is a value such that (100 − p) percent of the measurements fall at or below the value. Answer: FALSE Explanation: The pth percentile is a value such that p percent of the measurements fall at or below the value. Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 15) Chebyshev's Theorem is only of practical use when analyzing a non-mound-shaped population that is not very skewed. Answer: TRUE Explanation: This theorem gives large intervals containing reasonably large fractions of the population units no matter what the population's shape might be. Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-03 Use the Empirical Rule and Chebyshev's Theorem to describe variation. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 16) Z-score is often used as a measure of risk. Answer: FALSE Explanation: Z-score is used to measure a measurement's distance from the mean. Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-03 Use the Empirical Rule and Chebyshev's Theorem to describe variation. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 128 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 17) A correlation coefficient close to −1 says x and y are highly related. Answer: TRUE Explanation: This means they have a strong tendency to move together in a straight-line fashion. Difficulty: 1 Easy Topic: Covariance, Correlation, and the Least Squares Line Learning Objective: 03-05 Compute and interpret covariance, correlation, and the least squares line. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 18) The line that minimizes the sum of the squared horizontal (x) distances between the points on the scatter plot and the line is the least squares line. Answer: FALSE Explanation: The definition of the least squares line is the line that minimizes the sum of the squared vertical distances (y) between the points. Difficulty: 3 Hard Topic: Covariance, Correlation, and the Least Squares Line Learning Objective: 03-05 Compute and interpret covariance, correlation, and the least squares line. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 19) The weights that are used in calculating a weighted mean will vary depending on the situation. Answer: TRUE Explanation: The idea is to choose weights that represent the relative importance of the measurements in the population or sample. Difficulty: 2 Medium Topic: Weighted Means and Grouped Data Learning Objective: 03-06 Compute and interpret weighted means and the mean standard deviation of grouped data. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 129 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 20) Data summarized in a frequency distribution or histogram form are often called weighted data. Answer: FALSE Explanation: Data summarized in a frequency distribution or histogram form are called grouped data. Difficulty: 2 Medium Topic: Weighted Means and Grouped Data Learning Objective: 03-06 Compute and interpret weighted means and the mean standard deviation of grouped data. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 21) In the calculation of a mean for grouped data, we assume that the average of the measurements in each class equals the class midpoint. Answer: TRUE Explanation: We do this because we cannot compute and exact value for the mean. Difficulty: 2 Medium Topic: Weighted Means and Grouped Data Learning Objective: 03-06 Compute and interpret weighted means and the mean standard deviation of grouped data. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 22) The geometric mean is the rate of change that yields better wealth at the end of a set of time periods than the actual returns. Answer: FALSE Explanation: The definition of geometric mean is the rate of change that yields the same wealth at the end of several time periods as do actual returns. Difficulty: 3 Hard Topic: Geometric Mean Learning Objective: 03-07 Compute and interpret the geometric mean. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 130 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 23) When calculating the geometric mean, a quantity of 1 is added to the nth root of the product (1 + R1)(1 + R2) . . . (1 + Rn). Answer: FALSE Explanation: When calculating the geometric mean, 1 is subtracted from the nth root of the product. Difficulty: 3 Hard Topic: Geometric Mean Learning Objective: 03-07 Compute and interpret the geometric mean. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 24) The ending value of an initial investment can be calculated using weighted means. Answer: FALSE Explanation: The ending value of an initial investment is calculated using geometric mean. Difficulty: 2 Medium Topic: Geometric Mean Learning Objective: 03-07 Compute and interpret the geometric mean. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 25) A normal population has 99.73 percent of the population measurements within ________ standard deviation(s) of the mean. A) 1 B) 2 C) 3 D) 4 Answer: C Explanation: This is part of the Empirical Rule for a normally distributed population. Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-03 Use the Empirical Rule and Chebyshev's Theorem to describe variation. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 131 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 26) All of the following are measures of central tendency except the ________. A) range B) mode C) mean D) median Answer: A Explanation: The range gives the lowest to the highest value in the sample or population. Difficulty: 1 Easy Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 27) Which percentile describes the first quartile, Q1? A) 25th B) 50th C) 75th D) 100th Answer: A Explanation: This is denoted at Q1, a value below which approximately 25 percent of the measurements lie. Difficulty: 1 Easy Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 132 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 28) Which percentile describes the third quartile, Q3? A) 25th B) 50th C) 75th D) 100th Answer: C Explanation: This is denoted as Q3, a value below which approximately 75 percent of the measurements lie. Difficulty: 1 Easy Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 29) Which of the following is influenced the least by the occurrence of extreme values in a sample? A) mean B) median C) geometric mean D) weighted mean Answer: B Explanation: The median looks at the middle of a sample or population and does not take into effect low or high values. Difficulty: 2 Medium Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 133 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 30) If a population distribution is skewed to the right, then, given a random sample from that population, one would expect that the ________. A) median would be greater than the mean B) mode would be equal to the mean C) median would be less than the mean D) median would be equal to the mean Answer: C Explanation: The median in this case would be a better representation of the population — showing where most of the numbers congregate. Difficulty: 3 Hard Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Evaluate AACSB: Reflective Thinking Accessibility: Keyboard Navigation 31) If the mean, median, and mode for a given population are all equal and the relative frequency curve has matching tails to the right and left, then we would describe the shape of the distribution of the population as ________. A) bimodal B) skewed to the right C) symmetrical D) skewed to the left Answer: C Explanation: A symmetrical bell curve. Difficulty: 3 Hard Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 134 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 32) A disadvantage of using grouping (a frequency table) with sample data is that A) calculations involving central tendency and variation are more complicated than central tendency and variation calculations based on ungrouped data. B) the descriptive statistics are less precise than the descriptive statistics obtained using ungrouped data. C) the interpretation of the grouped data descriptive statistics is meaningless. D) it is much more difficult to summarize the information than it is with the ungrouped data. Answer: B Explanation: This is because we do not have access to the individual values; only the grouped data values. Difficulty: 3 Hard Topic: Weighted Means and Grouped Data Learning Objective: 03-06 Compute and interpret weighted means and the mean standard deviation of grouped data. Bloom's: Evaluate AACSB: Reflective Thinking Accessibility: Keyboard Navigation 33) When using Chebyshev's Theorem to obtain the bounds for 99.73 percent of the values in a population, the interval generally will be ________ the interval obtained for the same percentage if a normal distribution is assumed (Empirical Rule). A) shorter than B) wider than C) the same as Answer: B Explanation: This is due to the fact that Chebyshev's Theorem is used for non-mound shaped populations. Difficulty: 3 Hard Topic: Measures of Variation Learning Objective: 03-03 Use the Empirical Rule and Chebyshev's Theorem to describe variation. Bloom's: Apply AACSB: Reflective Thinking Accessibility: Keyboard Navigation 135 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 34) A quantity that measures the variation of a population or a sample relative to its mean is called the ________. A) range B) standard deviation C) coefficient of variation D) variance E) interquartile range Answer: C Explanation: The formula is the standard deviation divided by the mean then multiplied by 100. Difficulty: 1 Easy Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 35) As a measure of variation, the sample ________ is easy to understand and compute. It is based on the two extreme values and therefore may reflect an extreme measurement that is not entirely representative of the data set's variation. A) range B) standard deviation C) variance D) interquartile range E) coefficient of variation Answer: A Explanation: The range simply gives the highest and lowest numbers and does not give any central tendencies about the data. Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 136 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 36) A measurement located outside the upper limits of a box-and-whiskers display is ________. A) always in the first quartile B) an outlier C) always the largest value in the data set D) within the lower limits Answer: B Explanation: The box gives you the range from the first to the third quartile. Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 37) Another name for the 50th percentile is the ________. A) mean B) first quartile C) median D) mode E) third quartile Answer: C Explanation: The median is the middle number of a sample or population. Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 137 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 38) The measurement in a sample or a population that occurs most frequently is the ________. A) mode B) mean C) median D) outlier E) average Answer: A Explanation: There can be two modes. Difficulty: 2 Medium Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 39) The average of the squared deviations of the individual population measurement from the population mean is the ________. A) standard deviation B) mean C) variance D) median E) range Answer: C Explanation: This number is represented by sigma and is calculated via the standard deviation. Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 138 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 40) If the mean is greater than the median, then the relative frequency curve is most likely to be ________. A) skewed right B) skewed left C) symmetrical D) bimodal Answer: A Explanation: The median is not affected by outliers. Difficulty: 2 Medium Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 41) The ________ is the positive square root of the sample variance. A) sample mean B) sample standard deviation C) range D) median E) population standard deviation Answer: B Explanation: It is represented by sigma and shows how far values are from the mean. Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 139 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 42) The ________ is a quantity that measures the variation of a population or sample relative to its mean. A) mean B) standard deviation C) range D) coefficient of variation E) Z-score Answer: D Explanation: It is found by dividing the standard deviation by the mean and multiplying by 100. Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 43) An interval that contains a specified percentage of the individual measurements is called a(n) ________ interval. A) three-sigma B) tolerance C) normal D) empirical Answer: B Explanation: It can be used with the normally distributed population. Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-03 Use the Empirical Rule and Chebyshev's Theorem to describe variation. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 140 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 44) As the coefficient of variation ________, risk ________. A) increases; decreases B) decreases; increases C) increases; increases D) remains constant; increases Answer: C Explanation: The coefficient of variation can be used as a measure of risk because it can measure the rate on return. Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-03 Use the Empirical Rule and Chebyshev's Theorem to describe variation. Bloom's: Evaluate AACSB: Reflective Thinking Accessibility: Keyboard Navigation 45) Which of the following is a measure of the strength of the linear relationship between x and y that is dependent on the units in which x and y are measured? A) covariance B) correlation coefficient C) slope D) least squares line Answer: A Explanation: This tells you how close the relationship is to a straight line between x and y. Difficulty: 2 Medium Topic: Covariance, Correlation, and the Least Squares Line Learning Objective: 03-05 Compute and interpret covariance, correlation, and the least squares line. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 141 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 46) If b0 = 32 and b1 = −4 and the predicted value of y is 14, what is the value of x? A) −24.0 B) 18.0 C) 4.5 D) .56 Answer: C Explanation: y − b1x = b0 14 − (−4)x = 32 4x = 18 x = 4.5 Difficulty: 3 Hard Topic: Covariance, Correlation, and the Least Squares Line Learning Objective: 03-05 Compute and interpret covariance, correlation, and the least squares line. Bloom's: Apply AACSB: Reflective Thinking Accessibility: Keyboard Navigation 47) In the least squares line, ________ is defined as rise/run. A) correlation coefficient B) predicted value of y C) y-intercept D) slope Answer: D Explanation: The slope can be positive or negative, and that determines the correlation. Difficulty: 1 Easy Topic: Covariance, Correlation, and the Least Squares Line Learning Objective: 03-05 Compute and interpret covariance, correlation, and the least squares line. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 142 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 48) In the calculation of a mean for grouped data, ________ are used. A) total sample size and sum of the midpoints of each class B) total sample size and sum of the weighted midpoints C) sum of the frequency of each class and the sum of the midpoints of each class D) sum of the frequency of each class and the sample midpoint Answer: B Explanation: Total sample size and sum of the weighted midpoint are used, so therefore we cannot make many predictions about the individual data. Difficulty: 3 Hard Topic: Weighted Means and Grouped Data Learning Objective: 03-06 Compute and interpret weighted means and the mean standard deviation of grouped data. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 49) The arithmetic mean is ________ larger than a weighted mean in a set of data that uses unequal weights. A) always B) sometimes C) never Answer: B Explanation: The arithmetic mean is useful, but it is not a good measure of the rate of change exhibited by a variable over time. Difficulty: 3 Hard Topic: Weighted Means and Grouped Data Learning Objective: 03-06 Compute and interpret weighted means and the mean standard deviation of grouped data. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 143 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 50) The constant return that yields the same wealth at the end of the investment period as do the actual returns is the ________. A) grouped mean B) geometric mean C) weighted mean D) arithmetic mean Answer: B Explanation: This helps to remedy the issue with the arithmetic mean since it is not useful to display change over time. Difficulty: 1 Easy Topic: Geometric Mean Learning Objective: 03-07 Compute and interpret the geometric mean. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 51) In a statistics class, the following 10 scores were randomly selected: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the mean? A) 71.5 B) 72.0 C) 77.0 D) 71.0 E) 73.0 Answer: A Explanation: 74 + 73 + 77 + 77 +71 + 68 + 65 + 77 + 67 + 66 ÷ 10 = 71.5 Difficulty: 1 Easy Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 144 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 52) In a statistics class, the following 10 scores were randomly selected: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the median? A) 71.5 B) 72.0 C) 77.0 D) 71.0 E) 73.0 Answer: B Explanation: 65, 66, 67, 68, 71, 73, 74, 77, 77, 77 (71 + 73) ÷ 2 = 72 Difficulty: 1 Easy Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 53) In a statistics class, the following 10 scores were randomly selected: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the mode? A) 71.5 B) 72.0 C) 77.0 D) 71.0 E) 73.0 Answer: C Explanation: 77 appears the most frequently in this data set. Difficulty: 1 Easy Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 145 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 54) In a hearing test, subjects estimate the loudness (in decibels) of a sound, and the results are: 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68. What is the mean? A) 70 B) 75 C) 68 D) 71 E) 80 Answer: A Explanation: 68 + 67 + 70 + 71 + 68 + 75 + 68 + 62 + 80 + 73 + 68 ÷ 11 = 70 Difficulty: 1 Easy Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 55) In a hearing test, subjects estimate the loudness (in decibels) of a sound, and the results are: 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68. What is the median? A) 70 B) 75 C) 68 D) 71 E) 80 Answer: C Explanation: 62, 67, 68, 68, 68, 68, 70, 71, 73, 75, 80 68 is the middle number. Difficulty: 1 Easy Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 146 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 56) In a hearing test, subjects estimate the loudness (in decibels) of a sound, and the results are: 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68. What is the mode? A) 70 B) 75 C) 68 D) 71 E) 80 Answer: C Explanation: 68 appears most frequently in this data set. Difficulty: 1 Easy Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 57) The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes): 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118. What is the mean? A) 114.15 B) 118 C) 148 D) 45 E) 115.5 Answer: A Explanation: Mean = sum of values/n = 1484/13 = 114.15 Difficulty: 1 Easy Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 147 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 58) The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes): 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118. What is the median? A) 114.15 B) 118 C) 148 D) 45 E) 115.5 Answer: B Explanation: To calculate median, put data measurements in ascending order. The median for an odd number of measurements is the middle measurement; median = 118. Difficulty: 1 Easy Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 59) The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes): 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118. What is the mode? A) 114.15 B) 118 C) 148 D) 45 E) 115.5 Answer: B Explanation: Mode is the value(s) that appears most frequently; mode = 118 (occurs three times). Difficulty: 1 Easy Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 148 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 60) Quality control is an important issue at ACME Company, which manufactures light bulbs. To test the life-hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted: 378, 361, 350, 375, 200, 391, 375, 368, 321. What is the mean? A) 375 B) 368 C) 389.9 D) 200 E) 346.6 Answer: E Explanation: Mean = sum of values/n = 3119/9 = 346.56, or 346.6. Difficulty: 1 Easy Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 61) Quality control is an important issue at ACME Company, which manufactures light bulbs. To test the life-hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted: 378, 361, 350, 375, 200, 391, 375, 368, 321. What is the median? A) 375 B) 368 C) 389.9 D) 200 E) 346.6 Answer: B Explanation: To calculate median, put data measurements in ascending order. The median for an odd number of measurements is the middle measurement; median = 368. Difficulty: 1 Easy Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 149 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 62) Quality control is an important issue at ACME Company, which manufactures light bulbs. To test the life-hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted: 378, 361, 350, 375, 200, 391, 375, 368, 321. What is the mode? A) 375 B) 368 C) 389.9 D) 200 E) 346.6 Answer: A Explanation: Mode is the value(s) that appears most frequently; mode = 375 (occurs two times). Difficulty: 1 Easy Topic: Describing Central Tendency Learning Objective: 03-01 Compute and interpret the mean, median, and mode. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 63) Find the coefficient of variation for IQ tests with a mean of 100 and a standard deviation of 15. A) 15.0 B) 6.7 C) .15 D) 1.5 E) 67 Answer: A Explanation: Coefficient of variation = (Std dev/mean) × 100 = (15/100) × 100 = 15 Difficulty: 3 Hard Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 150 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 64) Find the z-score for an IQ test score of 142 when the mean is 100 and the standard deviation is 15. A) 42 B) 2.8 C) 18.78 D) 1.27 E) −2.8 Answer: B Explanation: Z-score = (x − mean)/std dev = (142 − 100)/15 = 42/15 = 2.8 Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 65) Find the z-score for an IQ test score of 92 when the mean is 100 and the standard deviation is 15. A) .53 B) .77 C) −.77 D) −.53 E) −8.00 Answer: D Explanation: Z-score = (x − mean)/std dev = (92 − 100)/15 = −8/15 = −.53 Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 151 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 66) Find the z-score for an IQ test score of 118 when the mean is 100 and the standard deviation is 15. A) 1.2 B) 1.0 C) 18.0 D) −1.03 E) −1.2 Answer: A Explanation: Z-score = (x − mean)/std dev = (118 − 100)/15 = 18/15 = 1.2 Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 67) Find the z-score for an IQ test score of 125 when the mean is 100 and the standard deviation is 15. A) 25 B) 1.1 C) 1.67 D) −1.1 E) −1.67 Answer: C Explanation: Z-score = (x − mean)/std dev = (125 − 100)/15 = 25/15 = 1.67 Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 152 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 68) Using Chebyshev's Theorem, find the interval that contains at least 93.75 percent of all measurements when the mean = 2.549 and s = 1.828. A) [−2.935, 8.033] B) [−1.107, 6.205] C) [−26.699, 31.797] D) [2.435, 2.663] E) [−4.763, 9.861] Answer: E Explanation: 1 − (1/k2) = .9375; 1/k2 = 1 − .9375; 1/k = ;k=4 Difficulty: 3 Hard Topic: Measures of Variation Learning Objective: 03-03 Use the Empirical Rule and Chebyshev's Theorem to describe variation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 69) According to a survey of the top 10 employers in a major city in the Midwest, a worker spends an average of 413 minutes a day on the job. Suppose the standard deviation is 26.8 minutes, and the time spent is approximately a normal distribution. What are the times within which approximately 68.26 percent of all workers will fall? A) [394.8, 431.2] B) [386.2, 439.8] C) [372.8, 453.2] D) [359.4, 466.6] E) [332.6, 493.4] Answer: B Explanation: 413 − 26.8 = 386.2 413 + 26.8 = 439.8 Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-03 Use the Empirical Rule and Chebyshev's Theorem to describe variation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 153 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 70) According to a survey of the top 10 employers in a major city in the Midwest, a worker spends an average of 413 minutes a day on the job. Suppose the standard deviation is 26.8 minutes and the time spent is approximately a normal distribution. What are the times within which approximately 99.73 percent of all workers will fall? A) [305.8, 520.2] B) [386.2, 439.8] C) [372.8, 453.2] D) [359.4, 466.6] E) [332.6, 493.4] Answer: E Explanation: 3(26.8) − 413 = 332.6 3(26.8) + 413 = 493.4 Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-03 Use the Empirical Rule and Chebyshev's Theorem to describe variation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 71) According to Chebyshev's theorem, at least what proportion of the data will be within μ ± kσ for k = 2? A) 68% B) 50% C) 25% D) 75% E) 34% Answer: D Explanation: For any values of k greater than 1, at least 100(1 − 1 /k2)% of the population measurements lie in the interval. Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-03 Use the Empirical Rule and Chebyshev's Theorem to describe variation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 154 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 72) Using Chebyshev's theorem, approximate the minimum proportion of the data that will be within μ ± kσ for k = 1.6. A) 39% B) 58% C) 68% D) 61% E) 92% Answer: D Explanation: 100(1 − 1 /k2)% = 100(1 − 1 /1.62)% = 61% Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-03 Use the Empirical Rule and Chebyshev's Theorem to describe variation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 73) Using Chebyshev's theorem, approximate the minimum proportion of the data that will be within μ ± kσ for k = 3.2. A) 90% B) 95% C) 84% D) 97% E) 10% Answer: A Explanation: 100(1 − 1 /k2)% = 100(1 − 1 /3.22)% = 90% Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-03 Use the Empirical Rule and Chebyshev's Theorem to describe variation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 155 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 74) According to Chebyshev's theorem, a range of how many standard deviations would include at least 80 percent of the values? A) 5.0 B) 2.2 C) 2.5 D) 1.6 E) 2.0 Answer: B Explanation: 100(1 − 1 /k2)% = 100(1 − 1 /2.22)% = 80% Difficulty: 3 Hard Topic: Measures of Variation Learning Objective: 03-03 Use the Empirical Rule and Chebyshev's Theorem to describe variation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 75) In a statistics class, 10 scores were randomly selected with the following results (mean = 71.5): 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the range? A) 22.72 B) 12.00 C) 4.77 D) 516.20 E) 144.00 Answer: B Explanation: 65, 66, 67, 68, 71, 73, 74, 77, 77, 77 77 − 65 = 12 Difficulty: 1 Easy Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 156 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 76) In a statistics class, 10 scores were randomly selected with the following results (mean = 71.5): 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the variance? A) 22.72 B) 12.00 C) 4.77 D) 516.20 E) 144.00 Answer: A Explanation: (74 − 71.5) = 2.5 squared = 6.25 (73 − 71.5) = 1.5 squared = 2.25 (77 − 71.5) = 5.5 squared = 30.25 (77 − 71.5) = 5.5 squared = 30.25 (71 − 71.5) = 0.5 squared = 0.25 (68 − 71.5) = −3.5 squared = 12.25 (65 − 71.5) = −6.5 squared = 42.25 (77 − 71.5) = 5.5 squared = 30.25 (67 − 71.5) = −4.5 squared = 20.25 (66 − 71.5) = −5.5 squared = 30.25 (6.25 + 2.25 + 30.25 + 30.25 + 0.25 + 12.25 +42.25 + 30.25 + 20.25 + 30.25) = 204.5 / 9 = 22.72 Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 77) In a statistics class, 10 scores were randomly selected with the following results (mean = 71.5): 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the standard deviation? A) 22.72 B) 12.00 C) 4.77 D) 516.20 E) 144.00 Answer: C Explanation: You take the square root of 22.71 = 4.77 Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 157 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 78) In a hearing test, randomly selected subjects estimate the loudness (in decibels) of a sound, and the results are (mean = 70): 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68. What is the range? A) 18 B) 4.73 C) 22.40 D) 324 E) 6.76 Answer: A Explanation: 62, 67, 68, 68, 68, 68, 70, 71, 73, 75, 80 80 − 62 = 18 Difficulty: 1 Easy Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 158 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 79) In a hearing test, randomly selected subjects estimate the loudness (in decibels) of a sound, and the results are (mean = 70): 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68. What is the variance? A) 18 B) 4.73 C) 22.40 D) 324 E) 6.76 Answer: C Explanation: 62, 67, 68, 68, 68, 68, 70, 71, 73, 75, 80 (62 − 70)= -8 squared = 64 (67 − 70)= -3 squared = 9 (68 − 70)= -2 squared = 4 (68 − 70)= -2 squared = 4 (68 − 70)= -2 squared = 4 (68 − 70)= -2 squared = 4 (70 − 70)= 0 squared = 0 (71 − 70)= 1 squared = 1 (73 − 70)= 2 squared = 4 (75 − 70)= 5 squared = 25 (80 − 70)= 10 squared = 100 (64 + 9 + 4 + 4 + 4 + 4 + 0 + 1 + 4 + 25 + 100) = 224 / 10 = 22.40 Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 159 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 80) In a hearing test, randomly selected subjects estimate the loudness (in decibels) of a sound, and the results are (mean = 70): 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68. What is the standard deviation? A) 18 B) 4.73 C) 22.40 D) 324 E) 6.76 Answer: B Explanation: You take the square root of 22.40 = 4.73 Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 81) The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes; mean = 114.15): 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118. What is the range? A) 103 B) 23.62 C) 557.97 D) 128.8 E) 115 Answer: A Explanation: Range = largest value − smallest value = 148 − 45 = 103 Difficulty: 1 Easy Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 160 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 82) The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes; mean = 114.15): 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118. What is the variance? A) 103 B) 23.62 C) 557.97 D) 128.8 E) 115 Answer: C Explanation: Variance = [Σ (x− mean)2]/(n − 1) = 6695.69/12 = 557.97 Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 83) The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes; mean = 114.15): 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118. What is the standard deviation? A) 103 B) 23.62 C) 557.97 D) 128.8 E) 115 Answer: B Explanation: Std Dev = = = = = 23.62 Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 161 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 84) Quality control is an important issue at ACME Company, which manufactures light bulbs. To test the life-hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted (mean = 346.6). 378, 361, 350, 375, 200, 391, 375, 368, 321 What is the range? A) 342.43 B) 3424.3 C) 58.5 D) 191 E) 10,609 Answer: D Explanation: Range = largest value − smallest value = 391 − 200 = 191 Difficulty: 1 Easy Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 85) Quality control is an important issue at ACME Company, which manufactures light bulbs. To test the life hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted (mean = 346.6). 378, 361, 350, 375, 200, 391, 375, 368, 321 What is the variance? A) 342.43 B) 3424.3 C) 58.5 D) 191 E) 10,609 Answer: B Explanation: Variance = [Σ (x− mean)2]/(n − 1) = 27,394.24/8 = 3424.28 Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 162 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 86) Quality control is an important issue at ACME Company, which manufactures light bulbs. To test the life-hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted (mean = 346.6). 378, 361, 350, 375, 200, 391, 375, 368, 321 What is the standard deviation? A) 342.43 B) 3424.3 C) 58.5 D) 191 E) 10,609 Answer: C Explanation: Std Dev = = = = = 58.5 Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 87) In a statistics class, 10 scores were randomly selected, with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the 90th percentile? A) 77 B) 73 C) 74 D) 67 E) 65.9 Answer: A Explanation: 65, 66, 67, 68, 71, 73, 74, 77, 77, 77 (90/100)n = (90/100)(10) = 9th position = 77 Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 163 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 88) In a statistics class, 10 scores were randomly selected with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the third quartile? A) 65.9 B) 67.3 C) 66.75 D) 73.85 E) 77.0 Answer: E Explanation: 65, 66, 67, 68, 71, 73, 74, 77, 77, 77 (75/100)n = (75/100)(10) = 7.5th position so round up to 8 = 77 Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 89) In a statistics class, 10 scores were randomly selected with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the first quartile? A) 65.9 B) 67.3 C) 67.0 D) 73.85 E) 77.0 Answer: C Explanation: 65, 66, 67, 68, 71, 73, 74, 77, 77, 77 (25/100)n = (25/100)(10) = 2.5th position so round up to 3 = 67 Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 164 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 90) In a statistics class, 10 scores were randomly selected, with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the 10th percentile? A) 65.5 B) 67.3 C) 66.75 D) 73.85 E) 77.0 Answer: A Explanation: 65, 66, 67, 68, 71, 73, 74, 77, 77, 77 (10/100)n = (10/100)(10) = 1st position = 65 + 66 / 2 = 65.5 Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 91) In a statistics class, 10 scores were randomly selected with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the 65th percentile? A) 65.5 B) 67.3 C) 66.75 D) 74.0 E) 77.0 Answer: D Explanation: 65, 66, 67, 68, 71, 73, 74, 77, 77, 77 (65/100)n = (65/100)(10) = 6.5th position, so round up to 7 = 74 Difficulty: 3 Hard Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 165 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 92) In a statistics class, 10 scores were randomly selected with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What is the IQR? A) 12.00 B) 5.25 C) 10 D) 5.00 E) 11.00 Answer: C Explanation: IQR = Q3− Q1 = 77 − 67 = 10 Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 93) In a statistics class, 10 scores were randomly selected with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What are the lower and upper limits of a box-and-whiskers display of this data? A) 67, 77 B) 57, 87 C) 37, 107 D) 52, 92 E) 47, 97 Answer: D Explanation: Lower limit: Q1− 1.5 IQR = 67 − 15 = 52. Upper limit: Q3 + 1.5 IQR = 77 + 15 = 92. Difficulty: 3 Hard Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 166 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 94) The company financial officer was interested in the average cost of PCs that had been purchased in the past six months. She took a random sample of the price of 10 computers, with the following results. $3,250, $1,127, $2,995, $3,250, $3,445, $3,449, $1,482, $6,120, $3,009, $4,000 What is the 90th percentile? A) $1,446.50 B) $3,449.00 C) $3,415.75 D) $4,000.00 E) $5,060.00 Answer: E Explanation: Place scores in ascending order and calculate the index = (p/100)n = (90/100) × 10 = 9. When the index is an integer, take the average of the i and i+1 values: (4000 + 6120)/2 = $5060. Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 95) The company financial officer was interested in the average cost of PCs that had been purchased in the past six months. She took a random sample of the price of 10 computers, with the following results. $3,250, $1,127, $2,995, $3,250, $3,445, $3,449, $1,482, $6,120, $3,009, $4,000 What is the third quartile? A) $1,446.50 B) $2,617.00 C) $3,415.75 D) $3,449.00 E) $4,212.00 Answer: D Explanation: Place scores in ascending order and calculate the index = (p/100)n = (75/100) × 10 = 7.5. When the index is not an integer, round up to the next integer to obtain the index value: 7.5 rounds to 8; the eighth value is $3,449. Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 96) The company financial officer was interested in the average cost of PCs that had been 167 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. purchased in the past six months. She took a random sample of the price of 10 computers, with the following results. $3,250, $1,127, $2,995, $3,250, $3,445, $3,449, $1,482, $6,120, $3,009, $4,000 What is the first quartile? A) $1,446.50 B) $2,995.00 C) $3,415.75 D) $3,587.00 E) $4,212.00 Answer: B Explanation: Place scores in ascending order and calculate the index = (p/100)n = (25/100) × 10 = 2.5. When the index is not an integer, round up to the next integer to obtain the index value: 2.5 rounds to 3; the third value is $2,995. Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 97) The company financial officer was interested in the average cost of PCs that had been purchased in the past six months. She took a random sample of the price of 10 computers, with the following results. $3,250, $1,127, $2,995, $3,250, $3,445, $3,449, $1,482, $6,120, $3,009, $4,000 What is the 10th percentile? A) $1,304.50 B) $2,617.00 C) $3,415.75 D) $3,587.00 E) $4,212.00 Answer: A Explanation: Place scores in ascending order and calculate the index = (p/100)n = (10/100) × 10 = 1. When the index is an integer, take the average of the i and i+1 values: (1127 + 1482)/2 = 1304.5. Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 98) The company financial officer was interested in the average cost of PCs that had been purchased in the past six months. She took a random sample of the price of 10 computers, with 168 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. the following results. $3,250, $1,127, $2,995, $3,250, $3,445, $3,449, $1,482, $6,120, $3,009, $4,000 What is the 65th percentile? A) $1,446.50 B) $2,617.00 C) $3,445.00 D) $3,587.00 E) $4,212.00 Answer: C Explanation: Place scores in ascending order and calculate the index = (p/100)n = (65/100) × 10 = 6.5. When the index is not an integer, round up to the next integer to obtain the index value: 6.5 rounds to 7; the seventh value is 3445. Difficulty: 3 Hard Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 99) The company financial officer was interested in the average cost of PCs that had been purchased in the past six months. She took a random sample of the price of 10 computers, with the following results. $3,250, $1,127, $2,995, $3,250, $3,445, $3,449, $1,482, $6,120, $3,009, $4,000 What is the IQR? A) 681 B) 454 C) 1362 D) 255 E) 6120 Answer: B Explanation: IQR = Q3− Q1 = 3449 − 2995 = 454 Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 169 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 100) The company financial officer was interested in the average cost of PCs that had been purchased in the past six months. She took a random sample of the price of 10 computers, with the following results. $3,250, $1,127, $2,995, $3,250, $3,445, $3,449, $1,482, $6,120, $3,009, $4,000 What are the lower and upper limits of a box-and-whiskers display of this data? A) 2541, 3903 B) 2768, 3676 C) 2087, 4357 D) 2314, 4130 E) 1633, 2087 Answer: D Explanation: Lower limit = Q1 − 1.5 IQR = 2995 − (1.5 × 454) = 2314 Upper limit = Q3 + 1.5 IQR = 3449 + (1.5 × 454) = 4130 Difficulty: 3 Hard Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 101) The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes). 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118 What is the 90th percentile? A) 100.8 B) 118 C) 130 D) 112 E) 45 Answer: C Explanation: Place scores in ascending order and calculate the index = (p/100)n = (90/100) × 13 = 11.7. When the index is not an integer, round up to the next integer to obtain the index value: 11.7 rounds to 12; the 12th value is 130. Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 170 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 102) The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes). 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118 What is the third quartile? A) 100.8 B) 118 C) 130 D) 112 E) 121 Answer: E Explanation: Place scores in ascending order and calculate the index = (p/100)n = (75/100) × 13 = 9.75. When the index is not an integer, round up to the next integer to obtain the index value: 9.75 rounds to 10; the 10th value is 121. Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 171 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 103) The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes). 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118 What is the first quartile? A) 100.8 B) 118 C) 130 D) 116 E) 45 Answer: D Explanation: Place scores in ascending order and calculate the index = (p/100)n = (25/100) × 13 = 3.25. When the index is not an integer, round up to the next integer to obtain the index value: 3.25 rounds to 4; the fourth value is 116. Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 172 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 104) The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes). 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118 What is the 10th percentile? A) 99 B) 120 C) 130 D) 112 E) 45 Answer: A Explanation: Place scores in ascending order and calculate the index = (p/100)n = (10/100) × 13 = 1.3. When the index is not an integer, round up to the next integer to obtain the index value: 1.3 rounds to 2; the second value is 99. Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 173 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 105) The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes). 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118 What is the 65th percentile? A) 99 B) 120 C) 130 D) 112 E) 45 Answer: B Explanation: Place scores in ascending order and calculate the index = (p/100)n = (65/100) × 13 = 8.45. When the index is not an integer, round up to the next integer to obtain the index value: 8.45 rounds to 9; the ninth value is 120. Difficulty: 3 Hard Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 106) The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes). 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118 What is the IQR? A) 103 B) 5 C) 28 D) 30 E) 7 Answer: B Explanation: IQR = Q3 − Q1 = 121 − 116 = 5 Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 174 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 107) The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes). 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118 What are the lower and upper limits of a box-and-whiskers display of this data? A) 80.5, 154.00 B) 108.5, 128.5 C) 127.75, 138.25 D) 143.50, 154.00 E) 15.75, 31.50 Answer: B Explanation: Lower limit: Q1 − 1.5 IQR; upper limit: Q3 + 1.5 IQR; 116 − (1.5 × 5) = 108.5 for the lower limit, and 121 + (1.5 × 5) = 128.5 for the upper limit. Difficulty: 3 Hard Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 108) Compute the population variance of these data: 16, 18, 23, 21, 17, 16, 24, 23, 9, 17, 11, 16, 22, 10, 15, 14. A) 21.9 B) 3.87 C) 20.5 D) 17.0 E) 3.625 Answer: C Explanation: = = = = 20.5 Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 175 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 109) If the median of a data set is 760, the third quartile is 950, and the first quartile is 650, what is the interquartile range? A) 300 B) 190 C) 110 D) 150 E) 910 Answer: A Explanation: Interquartile range = 950 − 650 = 300 Difficulty: 2 Medium Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 110) Compute the sample standard deviation of the data set 6, 4, 2, 1, 4, 1. A) 1.83 B) 2.00 C) 1.41 D) 3.33 E) 4.00 Answer: B Explanation: Std Dev = = ; mean = 3; = =2 Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 176 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 111) The average lateness for one of the top airline companies is 10 minutes. The variance of the lateness measure is calculated as 9. An airplane arrived 13 minutes after the stated arrival time. Calculate the z-score for the lateness of this particular airplane. A) .33 B) .58 C) 1.33 D) .44 E) 1.00 Answer: E Explanation: Z= =1 Difficulty: 2 Medium Topic: Measures of Variation Learning Objective: 03-02 Compute and interpret the range, variance, and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 112) The average life of Canadian women is 73.75 years, and the standard deviation of the life expectancy of Canadian women is 6.5 years. Using Chebyshev's theorem, determine the minimum percentage of women in Canada whose life expectancy is between 64 and 83.5 years. A) 93.17% B) 68.26% C) 55.56% D) 88.89% E) 33.33% Answer: C Explanation: Determine the value of k: (83.5, 64) = 73.75 ± k(6.5); k = 1.5 1 − (1/k2) = 1 − (1/2.25) = .5556, or 55.56% Difficulty: 3 Hard Topic: Measures of Variation Learning Objective: 03-03 Use the Empirical Rule and Chebyshev's Theorem to describe variation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 177 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 113) The average life of Canadian women is 73.75 years, and the standard deviation of the life expectancy of Canadian women is 6.5 years. Based on Chebyshev's theorem, determine the upper and lower bounds on the average life expectancy of Canadian women such that at least 90 percent of the population is included. A) [12.09 135.41] B) [8.75 138.75] C) [53.20 94.30] D) [66.38 81.13] E) [67.25 80.25] Answer: C Explanation: 1− = .90 = .1 k2 = = 10; k = = 3.162 lower bound = 73.75 − (3.162)(6.5) = 53.2 upper bound = 73.75 + (3.162)(6.5) = 94.3 Difficulty: 3 Hard Topic: Measures of Variation Learning Objective: 03-03 Use the Empirical Rule and Chebyshev's Theorem to describe variation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 178 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 114) The following table shows the Price-to-Earnings ratio for a stereo equipment manufacturing company between 1998 and 2002. Year 1998 1999 2000 2001 2002 P/E Ratio 12.4 14.6 11.1 8.2 6.8 Determine the percentage change in the P/E ratios from 1998 to 1999. A) 15.07% B) 17.74% C) 20.72% D) −17.74% E) −15.07% Answer: B Explanation: 1= × 100 = 17.74% Difficulty: 2 Medium Topic: Geometric Mean Learning Objective: 03-07 Compute and interpret the geometric mean. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 179 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 115) The following table shows the Price-to-Earnings ratio for a stereo equipment manufacturing company between 1998 and 2002. Year 1998 1999 2000 2001 2002 P/E Ratio 12.4 14.6 11.1 8.2 6.8 Determine the percentage change in the P/E ratios from 1999 to 2000. A) 23.97% B) 31.53% C) 27.26% D) −31.53% E) −23.97% Answer: E Explanation: R2 = × 100 = -23.97% Difficulty: 2 Medium Topic: Geometric Mean Learning Objective: 03-07 Compute and interpret the geometric mean. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 180 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 116) The following table shows the Price-to-Earnings ratio for a stereo equipment manufacturing company between 1998 and 2002. The annual percentage growth rate of the P/E ratios is also calculated and given below. Year 1998 1999 2000 2001 2002 P/E Ratio 12.4 14.6 11.1 8.2 6.8 Growth Rate (%) 17.74 (1998-1999) -23.97 (1999-2000) -26.13 (2000-2001) -17.07 (2001-2002) Calculate the geometric mean growth rate increase or decrease over the period from 1998 to 2002. A) −.2592 B) −.1395 C) −.1816 D) .8616 E) .7417 Answer: B Explanation: Rg = −1 Rg = ( ) − 1 = −.1397 Difficulty: 2 Medium Topic: Geometric Mean Learning Objective: 03-07 Compute and interpret the geometric mean. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 181 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 117) Suppose that a company's annual sales were $1,200,000 in 1999. The annual growth rate of sales from 1999 to 2000 was 16 percent, from 2000 to 2001 it was −5 percent, and from 2001 to 2002 it was 22 percent. What is the geometric mean growth rate of sales over this three-year period? A) 7.68% B) 9.27% C) 10.37% D) 11.00% E) 14.33% Answer: C Explanation: Forecasted Sales = 1,200,000(1 + .1037)5 = 1,965,337 Difficulty: 2 Medium Topic: Geometric Mean Learning Objective: 03-07 Compute and interpret the geometric mean. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 182 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 118) The following frequency table summarizes the ages of 60 shoppers at the local grocery store. Age of the Shopper 15-23 24-32 33-41 42-50 51-59 60-68 Frequency 10 21 10 8 5 6 The sample mean for the above frequency table is calculated as 36.25. Calculate the approximate sample standard deviation for this data set. A) 192.49 B) 195.75 C) 26.83 D) 13.87 E) 13.99 Answer: E Explanation: Class Midpoint (Mi) 19 28 37 46 55 64 s2 = Mi-X −17.25 −8.25 .75 9.75 18.75 27.75 (Mi-X)2 297.5625 68.0625 .5625 95.0625 351.5625 770.0625 FiMi-X2 2,975.63 1,429.31 5.63 76.05 1,757.81 4,620.38 10,864.81 ≅ 184.149 s= = 13.57 years Difficulty: 2 Medium Topic: Weighted Means and Grouped Data Learning Objective: 03-06 Compute and interpret weighted means and the mean standard deviation of grouped data. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 183 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 119) Personnel managers usually want to know where a job applicant ranked in his or her graduating class. With a grade point average of 3.83, Michelle Robinson graduated above the 93rd percentile of her graduating class. What is the percentile rank of a student whose GPA was the median GPA? A) 25th B) 50th C) 75th D) 10th E) 93rd Answer: B Explanation: Median is the equivalent of the 50th percentile. Difficulty: 1 Easy Topic: Percentiles, Quartiles, and Box-and-Whisker Displays Learning Objective: 03-04 Compute and interpret percentiles, quartiles, and box-and-whiskers displays. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 184 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 120) The Rivertown city council is attempting to choose one of four sites (A, B, C, or D) as the location for its new emergency facility. After the new emergency facility becomes available for service, the current emergency facility will be shut down. The project manager has estimated the following response times in minutes from each of the proposed sites to the four areas that must be served by the emergency facility. Proposed Site A B C D Area Served 2 3 4.4 3.6 7.4 3.4 5.9 5.9 4.8 6.5 1 5.2 6.0 5.8 4.3 4 6.5 4.0 5.8 5.1 The number of emergency runs from the current emergency facility to each of the four areas over the past year is as follows: Area Number of runs 1 150 2 65 3 175 4 92 Compute the weighted mean response time from the proposed locations and determine which proposed site should be selected for the new emergency facility. A) site A B) site B C) site C D) site D Answer: A Explanation: mA = 4.76; mB = 4.86; mC = 5.85; mD = 5.32. Choose site A. Difficulty: 3 Hard Topic: Weighted Means and Grouped Data Learning Objective: 03-06 Compute and interpret weighted means and the mean standard deviation of grouped data. Bloom's: Apply; Analyze AACSB: Analytical Thinking Accessibility: Keyboard Navigation 185 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 121) Researchers wish to study fuel consumption rates based on speed. The data from the test car at 10 speeds are below. Speed 15 23 30 35 42 45 50 54 60 65 Miles/Gallon 14 17 20 24 26 23 18 15 60 10 It can be shown that for these data: = 41.9, = 17.8, = 2352.9, = 267.6, ( - ) = −270.2. Calculate the sample covariance. A) −270.2 B) −30.02 C) −27.02 D) −74.58 E) −82.86 Answer: B Explanation: sxy = = −270.2 / 9 = −30.02 Difficulty: 3 Hard Topic: Covariance, Correlation, and the Least Squares Line Learning Objective: 03-05 Compute and interpret covariance, correlation, and the least squares line. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 186 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 122) Researchers wish to study fuel consumption rates based on speed. The data from the test car at 10 speeds are below. Speed 15 23 30 35 42 45 50 54 60 65 Miles/Gallon 14 17 20 24 26 23 18 15 60 10 It can be shown that for these data: = 41.9, = 17.8, = 2352.9, = 267.6, ( − ) = −270.2. Calculate b1. Answer: −0.1148 = = ( − ) /(n − 1) = -270.2 /9 = −30.02 /(n − 1) = 2352.9) /9 = 261.43 b1 = -30.02/261.43 = −0.1148 Difficulty: 3 Hard Topic: Covariance, Correlation, and the Least Squares Line Learning Objective: 03-05 Compute and interpret covariance, correlation, and the least squares line. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 187 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 123) Researchers wish to study fuel consumption rates based on speed. The data from 10 cars are below. Speed 15 23 30 35 42 45 50 54 60 65 Miles/Gallon 14 17 20 24 26 23 18 15 60 10 It can be shown that for these data: = 41.9, = 17.8, = 2352.9, = 267.6, ( − ) = −270.2. Calculate the sample correlation coefficient. A) .12 B) −.12 C) −.36 D) −.34 E) .34 Answer: D Explanation: r = sxy/(sx sy) = −30.02/88.17 = −.34 Difficulty: 3 Hard Topic: Covariance, Correlation, and the Least Squares Line Learning Objective: 03-05 Compute and interpret covariance, correlation, and the least squares line. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 188 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 124) In a study of the factors that affect success in economics, data were collected for 8 business students. Scores on a calculus placement test are given with economics final exam scores. The data are below: Calculus Placement Score 17 21 11 16 15 11 24 27 Exam Final Score 73 66 64 61 70 71 90 68 It can be shown that for these data: = 17.75, = 70.38, = 237.50, = 545.875, ( − )= 140.75. Calculate the sample covariance. A) 140.75 B) 77.98 C) 33.93 D) 20.11 E) 17.59 Answer: D Explanation: = ( − ) /(n − 1) = 140.75 /7 = 20.11 Difficulty: 3 Hard Topic: Covariance, Correlation, and the Least Squares Line Learning Objective: 03-05 Compute and interpret covariance, correlation, and the least squares line. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 189 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 125) In a study of the factors that affect success in economics, data were collected for 8 business students. Scores on a calculus placement test are given with economics final exam scores. The data are below. Calculus Placement Score 17 21 11 16 15 11 24 27 Exam Final Score 73 66 64 61 70 71 90 68 It can be shown that for these data: = 17.75, = 70.38, = 237.50, = 545.875, ( − )= 140.75. Calculate the sample correlation coefficient. A) .15 B) .11 C) .39 D) −.39 E) −.11 Answer: C Explanation: − ) /(n − 1) = 140.75 /7 = 20.11 = ( = / (n − 1) = 237.50 /7 = 33.93 b1 = 20.11/33.93 = .593 Difficulty: 3 Hard Topic: Covariance, Correlation, and the Least Squares Line Learning Objective: 03-05 Compute and interpret covariance, correlation, and the least squares line. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 190 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 126) In a study of the factors that affect success in economics, data were collected for 8 business students. Scores on a calculus placement test are given with economics final exam scores. The data are below. Calculus Placement Score 17 21 11 16 15 11 24 27 Exam Final Score 73 66 64 61 70 71 90 68 It can be shown that for these data: = 17.75, = 70.38, = 237.50, = 545.875, ( − )= 140.75. Calculate b1. A) .15 B) .26 C) .59 D) −.59 E) −.26 Answer: C Explanation: r = Sxy /(Sx × Sy) = 20.11/51.44 = .39 Difficulty: 3 Hard Topic: Covariance, Correlation, and the Least Squares Line Learning Objective: 03-05 Compute and interpret covariance, correlation, and the least squares line. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 191 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 127) In a study of employee stock ownership plans, data were collected at seven companies on satisfaction with the plan and the amount of organization commitment. Satisfaction 5.05 4.12 5.39 4.17 4.00 4.49 5.40 Commitment 5.37 4.49 5.42 4.45 4.24 5.34 5.62 It can be shown that for these data = 4.66, = 4.99, = 2.23, = 1.95, ( − ) = 1.898. Calculate b1. Answer: .851 − ) /(n − 1) = 1.898/6 = .3164 = ( = / (n − 1) = 2.23/6 = .372 b1 = .3164/.372 = .851 Difficulty: 3 Hard Topic: Covariance, Correlation, and the Least Squares Line Learning Objective: 03-05 Compute and interpret covariance, correlation, and the least squares line. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 192 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 128) In an analysis of the relationship between the average weekly temperature in a major city and the per person consumption of ice cream (pints), a least squares line is defined by the equation 5.72 + .004x. Predict the average amount of ice cream consumed when it is 50° outside. Answer: 5.92 pints y = 5.72 + .004(50) = 5.92 Difficulty: 1 Easy Topic: Covariance, Correlation, and the Least Squares Line Learning Objective: 03-05 Compute and interpret covariance, correlation, and the least squares line. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 129) From the following table of values and corresponding sample sizes, calculate the weighted mean. Group 1 2 3 4 5 X 3.1 5.1 4.2 2.5 4.8 n 9 7 10 2 6 Answer: 4.1 (3.1 × 9 + 5.1 × 7 + 4.2 × 10 + 2.5 × 2 + 4.8 × 6)/34 = 139.4/34 = 4.1 Difficulty: 2 Medium Topic: Weighted Means and Grouped Data Learning Objective: 03-06 Compute and interpret weighted means and the mean standard deviation of grouped data. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 193 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 130) Using grouped data of 14 classes with a sample mean of 51 and a sample variance of 6.42, calculate the group sampled standard deviation. Answer: 2.53 = 2.53 Difficulty: 1 Easy Topic: Weighted Means and Grouped Data Learning Objective: 03-06 Compute and interpret weighted means and the mean standard deviation of grouped data. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 131) A random sample of 60 students in the business statistics course answered a survey on the average number of hours they spent on statistics each week. Unfortunately, the original data were lost and all that remains is the frequency table below. From these data, calculate the estimated sample mean. Class 1 2 3 4 5 Hrs 0-3 4-7 8-11 12-15 16-19 N 18 16 14 10 2 Hrs 0-3 4-7 8-11 12-15 16-19 N 18 16 14 10 2 60 Answer: 6.97 Class 1 2 3 4 5 Midpt 1.5 5.5 9.5 13.5 17.5 fM 27 88 133 135 35 418 6.97 Difficulty: 2 Medium Topic: Weighted Means and Grouped Data Learning Objective: 03-06 Compute and interpret weighted means and the mean standard deviation of grouped data. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 194 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 132) A random sample of 60 students in the business statistics course answered a survey on the average number of hours they spent on statistics each week. Unfortunately, the original data were lost and all that remains is the frequency table below. From these data, calculate the estimated sample standard deviation. Class 1 2 3 4 5 Hrs 0-3 4-7 8-11 12-15 16-19 N 18 16 14 10 2 60 Midpt 1.5 5.5 9.5 13.5 17.5 fM 27 88 133 135 35 418 fM 27 88 133 135 35 418 (M-μ)2 29.9209 2.1609 6.4009 42.6409 110.8809 Answer: 4.714 Class 1 2 3 4 5 Hrs 0-3 4-7 8-11 12-15 16-19 N 18 16 14 10 2 60 Midpt 1.5 5.5 9.5 13.5 17.5 f(M-μ)2 538.5762 34.5744 89.6126 426.409 221.7618 1310.934 Sample variance = (1310.934)/(n − 1) = 1310.934/59 = 22.21922 Sample standard deviation = = 4.713727 Difficulty: 3 Hard Topic: Weighted Means and Grouped Data Learning Objective: 03-06 Compute and interpret weighted means and the mean standard deviation of grouped data. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 195 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 133) A real estate appraiser is gathering housing sales data by street in the neighborhood in preparation for his next job. Listed below are the six streets and the average sales price and the houses sold in the last 12 months. Calculate the mean sales price for the neighborhood. Street Elm Maple Oak Pine Rose Petunia Avg Sales Price 159,999 210,998 185,000 202,632 175,500 352,941 N 1 6 4 4 5 3 Answer: $213,602 Street Elm Maple Oak Pine Rose Petunia Avg Sales Price 159,999 210,998 185,000 202,632 175,500 352,941 N 1 6 4 4 5 3 23 159,999 1,265,988 740,000 810,528 877,500 1,058,823 4,912,838 213,602 Difficulty: 2 Medium Topic: Weighted Means and Grouped Data Learning Objective: 03-06 Compute and interpret weighted means and the mean standard deviation of grouped data. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 196 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 134) A company CEO asked the marketing research department to find the average age of consumers who bought the most profitable product made by the company. From survey data gathered two years ago, the researchers found the following table. Calculate the average age to give to the CEO. Midpt of Age Class 17.5 23.5 29.5 35.5 41.5 52.5 N 65 100 220 250 120 85 Average age = 33.7 Answer: Midpt of Age Class 17.5 23.5 29.5 35.5 41.5 52.5 N 65 100 220 250 120 85 840 1137.5 2350 6490 8875 4980 4462.5 28295 33.68452 Difficulty: 1 Easy Topic: Weighted Means and Grouped Data Learning Objective: 03-06 Compute and interpret weighted means and the mean standard deviation of grouped data. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 197 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 135) Find the weighted mean per capita income for the following random sample of six cities in the Midwest. City A B C D E F Population 540,000 1,250,000 325,000 2,461,000 845,000 620,000 Per Capita Income $ 26,338 $ 28,455 $ 36,574 $ 33,690 $ 31,998 $ 29,442 Answer: $31,432 City A B C D E F Average Population 540,000 1,250,000 325,000 2,461,000 845,000 620,000 6,041,000 Per Capita Income $ 26,338 $ 28,455 $ 36,574 $ 33,690 $ 31,998 $ 29,442 31,432 $ $ $ $ $ $ $ 14,222,520,000 35,568,750,000 11,886,550,000 82,911,090,000 27,038,310,000 18,254,040,000 189,881,260,000 Difficulty: 2 Medium Topic: Weighted Means and Grouped Data Learning Objective: 03-06 Compute and interpret weighted means and the mean standard deviation of grouped data. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 198 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 136) An initial investment of $10,000 is observed over 3 years with a geometric mean return at the end of year 3 of .512. Determine the value of the investment after 3 years. Answer: $34,566 $10,000 (1 + .512)3 = 10,000(3.4566) = 34,566 Difficulty: 2 Medium Topic: Geometric Mean Learning Objective: 03-07 Compute and interpret the geometric mean. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 137) An initial investment of $10,000 has a value of $7,382 at the end of year 1. What is the rate of return for the first year? Answer: −26.18% R1 = ((7382 − 10,000)/10,000) = −2618/10,000 = −.2618 × 100 = −26.18% Difficulty: 2 Medium Topic: Geometric Mean Learning Objective: 03-07 Compute and interpret the geometric mean. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 199 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 138) An initial investment of $10,000 has a value of $7,382 at the end of year 1, a rate of return of 62.43 percent for year 2, and a geometric mean return at the end of year 3 of .512. Determine the rate of return for the third year. Answer: 188.3% for R3 Rg = .512 = (3√(R1 + 1)(R2 + 1)(R3 + 1)) − 1 1.512 = (3√(R1 + 1)(R2 + 1)(R3 + 1)) 1.512 = 3√(-.2618 + 1)(.6243 + 1)(R3 + 1) 3.457 = (1.199)(R3 + 1) 2.883 = R3 + 1 1.883 = R3 R3 = 1.883 × 100 = 188.3% Difficulty: 3 Hard Topic: Geometric Mean Learning Objective: 03-07 Compute and interpret the geometric mean. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 139) At the end of 2007, the IRA owned by Joe Smith had a value of $1.2 million. With a rate of return of −29.75 percent in 2008 and a rate of return of 2.98 percent in 2009, calculate the geometric mean rate of return for the two-year period. Answer: −.1495 Rg = − 1 = −.1495 Difficulty: 2 Medium Topic: Geometric Mean Learning Objective: 03-07 Compute and interpret the geometric mean. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 200 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 140) The geometric mean growth rate of sales for used cars in a geographic area from 2005 to 2009 was 16.42 percent. Annual sales in 2005 were $14.2 million. Find the ending value of sales after this four-year period. (Round your answer to 2 decimal places.) Answer: $26.09 million 14.2(1 + .1642)4 = 26.09 Difficulty: 2 Medium Topic: Geometric Mean Learning Objective: 03-07 Compute and interpret the geometric mean. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 141) Suppose that annual sales for a company were $3.6 million at the beginning of a three-year period and at the end had increased to $6.1 million. Find the geometric growth rate of sales. Answer: .19 3.6(1 + Rg)3 = 6.1 (1 + Rg)3 = 1.69 (1 + Rg) = 1.1911 Rg = .1911 Difficulty: 3 Hard Topic: Geometric Mean Learning Objective: 03-07 Compute and interpret the geometric mean. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 201 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 142) The rate of return for each of the past four years on a market fund are R1 = 2.4%, R2 = 1.0%, R3 = −3.2%, and R4 = .5%. Find the geometric mean rate of return. Answer: .0015 )−1 Rg = ( )−1 =( = 1.0015 − 1 = .0015 Difficulty: 3 Hard Topic: Geometric Mean Learning Objective: 03-07 Compute and interpret the geometric mean. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 143) Following a factor analysis of 15 personality characteristic ratings of politicians by a random sample of 40,000 registered voters, the following table of the first 7 factors and their corresponding eigenvalues and percentage of explained variation was produced. Which factors should an analyst choose when defining the characteristics of politicians? Factor Eigenvalue 1 2 3 4 5 6 7 7.504 2.062 1.468 1.209 .741 .484 .344 Percent of Variation 50.0 13.7 9.8 8.1 4.9 3.2 2.3 Answer: Factors 1, 2, 3, and 4 Use factors that have an eigenvalue greater than 1. Difficulty: 3 Hard Topic: Factor Analysis Learning Objective: 03-11 Interpret the information provided by factor analysis. Bloom's: Apply AACSB: Reflective Thinking; Analytical Thinking Accessibility: Keyboard Navigation 202 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 144) Interpret a lift ratio of .9259. Answer: 7.41 percent of customers with similar patterns are less likely to follow recommendation than a random customer. A lift ratio is calculated by dividing confidence percentage by support percentage. The difference from 1 is the percentage of a customer base that is or is not following recommendation from association rules. Difficulty: 3 Hard Topic: Association Rules Learning Objective: 03-08 Interpret the information provided by association rules. Bloom's: Apply AACSB: Reflective Thinking Accessibility: Keyboard Navigation 145) Interpret a lift ratio of 1.111. Answer: 11.1 percent of customers with similar patterns are more likely to follow recommendation than a random customer. A lift ratio is calculated by dividing confidence percentage by support percentage. The difference from 1 is the percentage of a customer base that is or is not following recommendation from association rules. Difficulty: 3 Hard Topic: Association Rules Learning Objective: 03-08 Interpret the information provided by association rules. Bloom's: Apply AACSB: Reflective Thinking Accessibility: Keyboard Navigation 203 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 1) In any probability situation, either an event or its complement must occur. Answer: TRUE Explanation: The probability of the experiment is that only one of the outcomes will occur. Difficulty: 2 Medium Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 2) An event is a collection of sample space outcomes. Answer: TRUE Explanation: It is also called experimental outcomes, and only one of these sample space outcomes will occur on a single repetition of the experiment. Difficulty: 1 Easy Topic: Probability and Events Learning Objective: 04-02 List the outcomes in a sample space and use the list to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 3) Two events are independent if the probability of one event is influenced by whether or not the other event occurs. Answer: FALSE Explanation: Independence of events means there is no influence. Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 204 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 4) Mutually exclusive events have a nonempty intersection. Answer: FALSE Explanation: Mutually exclusive events do not intersect (have no sample spaces in common). Difficulty: 2 Medium Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 5) A subjective probability is a probability assessment that is based on experience, intuitive judgment, or expertise. Answer: TRUE Explanation: This means that an individual injects their opinion and thought into whether an event is deemed a success or failure. Difficulty: 2 Medium Topic: Probability, Sample Spaces, and Probability Models Learning Objective: 04-01 Define a probability, a sample space, and a probability model. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 6) The probability of an event is the sum of the probabilities of the sample space outcomes that correspond to the event. Answer: TRUE Explanation: This helps us deal with the uncertainty of an event to determine the likelihood that an event will occur. Difficulty: 2 Medium Topic: Probability and Events Learning Objective: 04-02 List the outcomes in a sample space and use the list to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 205 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 7) If events A and B are mutually exclusive, then P(A|B) is always equal to zero. Answer: TRUE Explanation: This means that either one or the other has to occur—they both cannot occur at the same time. Difficulty: 3 Hard Topic: Some Elementary Probability Rules; Conditional Probability and Independence Learning Objective: 04-03 Use elementary probability rules to compute probabilities.; 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 8) If events A and B are independent, then P(A|B) is always equal to zero. Answer: FALSE Explanation: If events A and B are independent, then P(A|B) is always equal to P(A). Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 9) If events A and B are mutually exclusive, then P(A∩B) is always equal to zero. Answer: TRUE Explanation: They have no sample space outcomes in common. Difficulty: 1 Easy Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 10) Events that have no sample space outcomes in common, and therefore cannot occur simultaneously, are referred to as independent events. Answer: FALSE Explanation: This is a definition of mutually exclusive events. Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 206 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 11) The method of assigning probabilities when all outcomes are equally likely to occur is called the classical method. Answer: TRUE Explanation: This is the classic example of toss a coin either heads or tails — logic says that either outcome is equally as likely. Difficulty: 1 Easy Topic: Probability, Sample Spaces, and Probability Models Learning Objective: 04-01 Define a probability, a sample space, and a probability model. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 12) Bayes' Theorem uses prior probabilities with additional information to compute posterior probabilities. Answer: TRUE Explanation: The book gives the example of testing the entire population for HIV — and because of the prior probabilities given one would not test the population for HIV because there would be a high rate of false positives. Difficulty: 2 Medium Topic: Bayes' Theorem Learning Objective: 04-05 Use Bayes' Theorem to update prior probabilities to posterior probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 13) Bayes' Theorem is always based on two states of nature and three experimental outcomes. Answer: FALSE Explanation: Bayes' Theorem can have any number of states of nature and any number of experimental outcomes. Difficulty: 2 Medium Topic: Bayes' Theorem Learning Objective: 04-05 Use Bayes' Theorem to update prior probabilities to posterior probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 207 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 14) A probability model is a mathematic representation of a random phenomenon. Answer: TRUE Explanation: With probability, we are dealing with uncertainty of a specific experiment. Difficulty: 1 Easy Topic: Probability, Sample Spaces, and Probability Models Learning Objective: 04-01 Define a probability, a sample space, and a probability model. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 15) There are two types of probability distributions: discrete and binomial. Answer: FALSE Explanation: The two types are discrete and continuous. Binomial is a type of discrete probability distribution. Difficulty: 2 Medium Topic: Probability, Sample Spaces, and Probability Models Learning Objective: 04-01 Define a probability, a sample space, and a probability model. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 16) A random variable is a numerical value that is determined by the outcome of an experiment. Answer: TRUE Explanation: This random variable is called a probability distribution. Difficulty: 1 Easy Topic: Probability, Sample Spaces, and Probability Models Learning Objective: 04-01 Define a probability, a sample space, and a probability model. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 208 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 17) Two mutually exclusive events having positive probabilities are ________ dependent. A) always B) sometimes C) never Answer: A Explanation: Mutually exclusive events are always dependent on each other because if one option occurs the other cannot occur. Difficulty: 2 Medium Topic: Some Elementary Probability Rules; Conditional Probability and Independence Learning Objective: 04-03 Use elementary probability rules to compute probabilities.; 04-04 Compute conditional probabilities and assess independence. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 18) A ________ is a measure of the chance that an uncertain event will occur. A) random experiment B) sample space C) probability D) complement E) population Answer: C Explanation: With probability, we are dealing with uncertainty and are applying mathematical models to predict the chance of something occurring. Difficulty: 2 Medium Topic: Probability, Sample Spaces, and Probability Models Learning Objective: 04-01 Define a probability, a sample space, and a probability model. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 209 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 19) A manager has just received the expense checks for six of her employees. She randomly distributes the checks to the six employees. What is the probability that exactly five of them will receive the correct checks (checks with the correct names)? A) 1 B) 1/2 C) 1/6 D) 0 E) 1/3 Answer: D Explanation: If five have received the correct check, then it follows that the sixth employee will receive the correct check. Thus, the probability that exactly five will receive the correct check is 0. Difficulty: 3 Hard Topic: Probability, Sample Spaces, and Probability Models Learning Objective: 04-02 List the outcomes in a sample space and use the list to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 20) In which of the following are the two events A and B always independent? A) A and B are mutually exclusive. B) The probability of event A is influenced by the probability of event B. C) The intersection of A and B is zero. D) P(A|B) = P(B|A). E) The probability of event A is not influenced by whether event B occurs, or P(A|B) = P(A). Answer: E Explanation: The probability of event A is not influenced by whether event B occurs. All of the other options describe dependent events. Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 210 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 21) If two events are independent, we can ________ their probabilities to determine the intersection probability. A) divide B) add C) multiply D) subtract Answer: C Explanation: This is the multiplication rule for N independent events. Difficulty: 1 Easy Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 22) Events that have no sample space outcomes in common, and therefore cannot occur simultaneously, are ________. A) independent B) mutually exclusive C) intersections D) unions Answer: B Explanation: This is the classic example of flipping a coin — if you get heads you cannot also get tails. Difficulty: 2 Medium Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 211 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 23) If events A and B are independent, then the probability of simultaneous occurrence of event A and event B can be found with ________. A) P(A)·P(B) B) P(A)·P(B|A) C) P(B)·P(A|B) D) All of these choices are correct. Answer: D Explanation: All of these notations depict independent events. Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 24) The set of all possible outcomes for an experiment is called a(n) ________. A) sample space B) event C) experiment D) probability Answer: A Explanation: We must define the sample space outcomes so that on any single repetition of the experiment, only one sample space outcome will occur. Difficulty: 1 Easy Topic: Probability, Sample Spaces, and Probability Models Learning Objective: 04-01 Define a probability, a sample space, and a probability model. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 212 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 25) A ________ is the probability that one event will occur given that we know that another event already has occurred. A) sample space outcome B) subjective probability C) complement of events D) long-run relative frequency E) conditional probability Answer: E Explanation: The probability of A given B also known as the probability of A given that B has already occurred. Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 26) The ________ of two events X and Y is another event that consists of the sample space outcomes belonging to either event X or event Y or both events X and Y. A) complement B) union C) intersection D) conditional probability Answer: B Explanation: The probability that A or B or both will occur. Difficulty: 2 Medium Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 213 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 27) If P(A) > 0 and P(B) > 0 and events A and B are independent, then ________. A) P(A) = P(B) B) P(A|B) = P(A) C) P(A∩B) = 0 D) P(A∩B) = P(A) P(B∪A) Answer: B Explanation: This is the notation is for independent events. It can also be written as P(B|A) = P(B). Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 28) P(AUB) = P(A) + P(B) − P(A∩B) represents the formula for the ________. A) conditional probability B) addition rule C) addition rule for two mutually exclusive events D) multiplication rule Answer: B Explanation: You need to subtract out the mutually exclusive events because otherwise you would count them twice. Difficulty: 2 Medium Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 29) A(n) ________ is the set of all of the distinct possible outcomes of an experiment. A) sample space B) union C) intersection D) observation Answer: A Explanation: Probabilities must be assigned to the sample space outcomes. Difficulty: 2 Medium Topic: Probability, Sample Spaces, and Probability Models Learning Objective: 04-01 Define a probability, a sample space, and a probability model. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 214 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 30) The ________ of an event is a number that measures the likelihood that an event will occur when an experiment is carried out. A) outcome B) probability C) intersection D) observation Answer: B Explanation: Probability deals with the concept of measuring uncertainty. Difficulty: 1 Easy Topic: Probability, Sample Spaces, and Probability Models Learning Objective: 04-01 Define a probability, a sample space, and a probability model. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 31) When the probability of one event is influenced by whether or not another event occurs, the events are said to be ________. A) independent B) dependent C) mutually exclusive D) experimental Answer: B Explanation: This means that if one event occurs, then another event will be more or less likely to occur because of the first event occurring. Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 215 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 32) A process of observation that has an uncertain outcome is referred to as a(n) ________. A) probability B) frequency C) conditional probability D) experiment Answer: D Explanation: When performing statistical studies, we collect data by performing a controlled experiment. Difficulty: 2 Medium Topic: Probability, Sample Spaces, and Probability Models Learning Objective: 04-01 Define a probability, a sample space, and a probability model. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 33) When the probability of one event is not influenced by whether or not another event occurs, the events are said to be ________. A) independent B) dependent C) mutually exclusive D) experimental Answer: A Explanation: This means that events A and B have nothing to do with one another. Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 34) A probability may be interpreted as a long-run ________ frequency. A) observational B) relative C) experimental D) conditional Answer: B Explanation: A relative frequency interpretation of probability is a mathematical idealization. Difficulty: 2 Medium Topic: Probability, Sample Spaces, and Probability Models Learning Objective: 04-01 Define a probability, a sample space, and a probability model. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 216 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 35) If events A and B are independent, then P(A|B) is equal to ________. A) P(B) B) P(A∩B) C) P(A) D) P(AUB) Answer: C Explanation: This is how independent events are denoted. Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 36) The simultaneous occurrence of events A and B is represented by the notation ________. A) AUB B) A|B C) A∩B D) B|A Answer: C Explanation: This is when events A and B occur at the same time. Difficulty: 1 Easy Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 217 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 37) A(n) ________ probability is a probability assessment that is based on experience, intuitive judgment, or expertise. A) experimental B) relative frequency C) objective D) subjective Answer: D Explanation: This is when an individual injects their personal opinion on if an event is judged as a success or failure. Difficulty: 2 Medium Topic: Probability, Sample Spaces, and Probability Models Learning Objective: 04-01 Define a probability, a sample space, and a probability model. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 38) A(n) ________ is a collection of sample space outcomes. A) experiment B) event C) set D) probability Answer: B Explanation: It is also called experimental outcomes. Difficulty: 1 Easy Topic: Probability and Events Learning Objective: 04-02 List the outcomes in a sample space and use the list to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 218 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 39) Probabilities must be assigned to each sample space outcome so that the probabilities of all the sample space outcomes add up to ________. A) 1 B) between 0 and 1 C) between −1 and 1 D) 0 Answer: A Explanation: The probability of an event is always a number between 0 and 1. All of the probabilities in a sample space add up to 1. Difficulty: 1 Easy Topic: Probability, Sample Spaces, and Probability Models Learning Objective: 04-01 Define a probability, a sample space, and a probability model. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 40) Probabilities must be assigned to sample space outcomes so that the probability assigned to each sample space outcome must be between ________, inclusive. A) 0 and 100 B) −100 and 100 C) 0 and 1 D) −1 and 1 Answer: C Explanation: All of these probabilities in the sample space must add up to 1. Difficulty: 1 Easy Topic: Probability, Sample Spaces, and Probability Models Learning Objective: 04-01 Define a probability, a sample space, and a probability model. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 219 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 41) The ________ of event X consists of all sample space outcomes that do not correspond to the occurrence of event X. A) independence B) complement C) conditional probability D) dependence Answer: B Explanation: Also known as the probability that X will not occur. Difficulty: 1 Easy Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 42) The ________ of two events A and B is the event that consists of the sample space outcomes belonging to both event A and event B. A) union B) intersection C) complement D) mutual exclusivity Answer: B Explanation: The event that occurs if both A and B occur. Difficulty: 1 Easy Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 43) Determine whether these two events are mutually exclusive: consumer with an unlisted phone number and a consumer who does not drive. A) mutually exclusive B) not mutually exclusive Answer: B Explanation: In this case, one does not determine the other. Difficulty: 1 Easy Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 44) Determine whether these two events are mutually exclusive: unmarried person and a person 220 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. with an employed spouse. A) mutually exclusive B) not mutually exclusive Answer: A Explanation: If you are unmarried you do not have a spouse. Difficulty: 1 Easy Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 45) Determine whether these two events are mutually exclusive: someone born in the United States and a U.S. citizen. A) mutually exclusive B) not mutually exclusive Answer: B Explanation: One event does not affect the other: You do not have to be born in the U.S. to be a U.S. citizen. Difficulty: 1 Easy Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 46) Determine whether these two events are mutually exclusive: voter who favors gun control and an unregistered voter. A) mutually exclusive B) not mutually exclusive Answer: A Explanation: If you are a voter then you cannot be an unregistered voter. Difficulty: 1 Easy Topic: Some Elementary Probability Rules; Conditional Probability and Independence Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 221 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 47) Determine whether these two events are mutually exclusive: someone with three sisters and someone with four siblings. A) mutually exclusive B) not mutually exclusive Answer: B Explanation: If you have four siblings, you could have three sisters or you could have three brothers. Difficulty: 1 Easy Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 48) Consider a standard deck of 52 playing cards, a randomly selected card from the deck, and the following events: R = red, B = black, A = ace, N = nine, D = diamond, and C = club. Are R and A mutually exclusive? A) Yes, mutually exclusive. B) No, not mutually exclusive. Answer: B Explanation: In this case, you can have a red ace or a black ace. Difficulty: 1 Easy Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 49) Consider a standard deck of 52 playing cards, a randomly selected card from the deck, and the following events: R = red, B = black, A = ace, N = nine, D = diamond, and C = club. Are R and C mutually exclusive? A) Yes, mutually exclusive. B) No, not mutually exclusive. Answer: A Explanation: Clubs are only black cards so you cannot have a red club. Difficulty: 1 Easy Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 222 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 50) Consider a standard deck of 52 playing cards, a randomly selected card from the deck, and the following events: R = red, B = black, A = ace, N = nine, D = diamond, and C = club. Are A and N mutually exclusive? A) Yes, mutually exclusive. B) No, not mutually exclusive. Answer: A Explanation: In this case, you cannot have both an Ace and a nine. Difficulty: 1 Easy Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 51) Consider a standard deck of 52 playing cards, a randomly selected card from the deck, and the following events: R = red, B = black, A = ace, N = nine, D = diamond, and C = club. Are N and C mutually exclusive? A) Yes, mutually exclusive. B) No, not mutually exclusive. Answer: B Explanation: There is a nine of clubs, but there is also a nine of hearts, spades and diamonds. Difficulty: 1 Easy Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 52) Consider a standard deck of 52 playing cards, a randomly selected card from the deck, and the following events: R = red, B = black, A = ace, N = nine, D = diamond, and C = club. Are D and C mutually exclusive? A) Yes, mutually exclusive. B) No, not mutually exclusive. Answer: A Explanation: In this case, you cannot have both a diamond and a club at the same time. Difficulty: 1 Easy Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 223 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 53) The probability model describing an experiment consists of A) sample space. B) probabilities of the sample space outcomes. C) sample space and probabilities of the sample space outcomes. D) independent events. E) random variables. Answer: C Explanation: They are also called experimental outcomes. Difficulty: 2 Medium Topic: Probability, Sample Spaces, and Probability Models Learning Objective: 04-01 Define a probability, a sample space, and a probability model. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 54) What is the probability of rolling a seven with a pair of fair dice? A) 6/36 B) 3/36 C) 1/36 D) 8/36 E) 7/36 Answer: A Explanation: Set up sample spaces: 36 total; 6 have combination adding to 7. Difficulty: 2 Medium Topic: Probability and Events Learning Objective: 04-02 List the outcomes in a sample space and use the list to compute probabilities. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 224 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 55) What is the probability of rolling a value higher than eight with a pair of fair dice? A) 6/36 B) 18/36 C) 10/36 D) 8/36 E) 12/36 Answer: C Explanation: Set up sample spaces: 36 total; 10 have combination adding to more than 8. Difficulty: 2 Medium Topic: Probability and Events Learning Objective: 04-02 List the outcomes in a sample space and use the list to compute probabilities. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 56) What is the probability that an even number appears on the toss of a die? A) 0.5 B) 0.33 C) 0.25 D) 0.67 E) 1.00 Answer: A Explanation: Set up sample spaces: 6 total; 2, 4, and 6 are even numbers. Difficulty: 1 Easy Topic: Probability and Events Learning Objective: 04-02 List the outcomes in a sample space and use the list to compute probabilities. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 225 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 57) What is the probability that a king appears in drawing a single card from a deck of 52 cards? A) 4/13 B) 1/13 C) 1/52 D) 1/12 E) 2/13 Answer: B Explanation: Set up sample spaces: 52; 4 kings in a deck. Difficulty: 3 Hard Topic: Probability and Events Learning Objective: 04-02 List the outcomes in a sample space and use the list to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 58) If we consider the toss of four coins as an experiment, how many outcomes does the sample space consist of? A) 8 B) 4 C) 16 D) 32 E) 2 Answer: C Explanation: 24 = 16 Difficulty: 3 Hard Topic: Counting Rules Learning Objective: 04-06 Use some elementary counting rules to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 226 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 59) What is the probability of at least one tail in the toss of three fair coins? A) 1/8 B) 4/8 C) 5/8 D) 7/8 E) 6/8 Answer: D Explanation: Set up sample spaces: 8 possibilities; only one has all heads; other 7 have at least one tail. Difficulty: 3 Hard Topic: Probability and Events Learning Objective: 04-02 List the outcomes in a sample space and use the list to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 60) A lot contains 12 items, and 4 are defective. If three items are drawn at random from the lot, what is the probability they are not defective? A) 0.3333 B) 0.2545 C) 0.5000 D) 0.2963 E) 0.0370 Answer: B Explanation: = .2545 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 227 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 61) A person is dealt 5 cards from a deck of 52 cards. What is the probability they are all clubs? A) 0.2500 B) 0.0962 C) 0.0769 D) 0.0010 E) 0.0005 Answer: E Explanation: = 0.0004951 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 62) A group has 12 men and 4 women. If 3 people are selected at random from the group, what is the probability that they are all men? A) 0.4219 B) 0.5143 C) 0.3929 D) 0.0156 E) 0.0045 Answer: C Explanation: = .392857 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 228 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 63) Container 1 has 8 items, 3 of which are defective. Container 2 has 5 items, 2 of which are defective. If one item is drawn from each container, what is the probability that both items are not defective? A) 0.3750 B) 0.3846 C) 0.1500 D) 0.6154 E) 0.2000 Answer: A Explanation: = .375 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 64) Container 1 has 8 items, 3 of which are defective. Container 2 has 5 items, 2 of which are defective. If one item is drawn from each container, what is the probability that the item from Container 1 is defective and the item from Container 2 is not defective? A) 0.3846 B) 0.2250 C) 0.3750 D) 0.6154 E) 0.1500 Answer: B Explanation: = .225 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 229 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 65) Container 1 has 8 items, 3 of which are defective. Container 2 has 5 items, 2 of which are defective. If one item is drawn from each container, what is the probability that only one of the items is defective? A) 0.2250 B) 0.6250 C) 0.2500 D) 0.4750 E) 0.1500 Answer: D Explanation: Container 1 P(Defective) = 3/8 = .375; Container 2 P(Defective) = 2/5 = .400 P(Both defective) = .375 × .400 = .150; P(Neither defective) = (1 – .375) × (1 – .40) = .375 P(Only one defective) = 1 – (.150 + .375) = .475 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 66) A coin is tossed 6 times. What is the probability that at least one head occurs? A) 63/64 B) 1/64 C) 1/36 D) 5/6 E) 1/2 Answer: A Explanation: (1/2)(1/2)(1/2)(1/2)(1/2)(1/2) = P(No Heads) = 1/64 1 – 1/64 = 63/64 Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 230 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 67) Given the standard deck of cards, what is the probability of drawing a red card, given that it is a face card? A) 0.500 B) 0.115 C) 0.231 D) 0.077 E) 0.308 Answer: A Explanation: P(Red | Face) = = = .5 Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 68) Given a standard deck of cards, what is the probability of drawing a face card, given that it is a red card? A) 0.115 B) 0.500 C) 0.231 D) 0.462 E) 0.308 Answer: C Explanation: P(Red | Face) = = = Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 231 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 69) A machine is made up of 3 components: an upper part, a middle part, and a lower part. The machine is then assembled. 5 percent of the upper parts are defective, 4 percent of the middle parts are defective, and 1 percent of the lower parts are defective. What is the probability that a machine is not defective? A) 0.1000 B) 0.9029 C) 0.8000 D) 0.0002 E) 0.7209 Answer: B Explanation: (.95)(.96)(.99) = .9029 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 70) A machine is produced by a sequence of operations. On average, one out of every 1000 machines produced is defective. What is the probability that two machines selected at random are both nondefective? A) 0.000999 B) 0.001 C) 0.002 D) 0.998 E) 0.500 Answer: D Explanation: (.999)(.999) = .998 Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 232 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 71) A pair of dice is thrown. What is the probability that one of the faces is a 3, given that the sum of the two faces is 9? A) 1/3 B) 1/36 C) 1/6 D) 1/2 E) 1/4 Answer: D Explanation: Set up sample spaces: 36 total; 4 total to 9; 2 of these have a three on the face. Given that there are 4 choices and 2 have a three, the probability is ½. Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 72) A card is drawn from a standard deck. What is the probability the card is an ace, given that it is a club? A) 1/52 B) 1/13 C) 4/13 D) 1/4 Answer: B Explanation: Set up sample space: 52 cards; 13 are clubs, one of which is an ace. Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 233 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 73) A card is drawn from a standard deck. Given that a face card is drawn, what is the probability it will be a king? A) 1/3 B) 1/13 C) 4/13 D) 1/12 E) 1/4 Answer: A Explanation: (4 kings)/(12 face cards) Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 74) Independently, a coin is tossed, a card is drawn from a deck, and a die is thrown. What is the probability of observing a head on the coin, an ace on the card, and a five on the die? A) 0.0064 B) 0.1000 C) 0.7436 D) 0.0096 E) 0.5000 Answer: A Explanation: 1/2 × 4/52 × 1/6 = 1/156 = 0.0064 Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 234 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 75) A family has two children. What is the probability that both are girls, given that at least one is a girl? A) 1/8 B) 1/4 C) 1/2 D) 1/3 E) 1/6 Answer: D Explanation: Set up sample space: 3 possible for the given statement BG, GB and GG; 2 of these have at least one girl; 1 has two girls so the probability that GG is 1 out of 3 or 1/3. Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 76) What is the probability of winning four games in a row, if the probability of winning each game individually is 1/2? A) 1/4 B) 1/8 C) 1/2 D) 3/16 E) 1/16 Answer: E Explanation: = Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 235 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 77) At a college, 70 percent of the students are women, and 50 percent of the students receive a grade of C. 25 percent of the students are neither female nor C students. Construct a contingency table. Answer: C Women Men 0.45 0.05 0.50 0.25 0.25 0.50 0.70 0.30 1.00 Difficulty: 3 Hard Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 78) At a college, 70 percent of the students are women, and 50 percent of the students receive a grade of C. 25 percent of the students are neither female nor C students. Use this contingency table. C Women Men 0.45 0.05 0.50 0.25 0.25 0.50 0.70 0.30 1.00 What is the probability that a student is female and a C student? A) .45 B) .50 C) .70 D) .25 E) .05 Answer: A Explanation: Read off contingency table = P(F ∩ C) = .45 Difficulty: 3 Hard Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 236 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 79) At a college, 70 percent of the students are women, and 50 percent of the students receive a grade of C. 25 percent of the students are neither female nor C students. Use this contingency table. C Women Men 0.45 0.05 0.50 0.25 0.25 0.50 0.70 0.30 1.00 What is the probability that a student is male and not a C student? A) .45 B) .50 C) .70 D) .25 E) .05 Answer: D Explanation: Read off contingency table: P(M ∩ not C) = .25 Difficulty: 3 Hard Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 237 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 80) At a college, 70 percent of the students are women, and 50 percent of the students receive a grade of C. 25 percent of the students are neither female nor C students. Use this contingency table. C Women Men 0.45 0.05 0.50 0.25 0.25 0.50 0.70 0.30 1.00 If a student is male, what is the probability he is a C student? A) 0.05 B) 0.10 C) 0.30 D) 0.17 E) 0.50 Answer: D Explanation: P(C | Male) = = .1667 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 238 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 81) At a college, 70 percent of the students are women, and 50 percent of the students receive a grade of C. 25 percent of the students are neither female nor C students. Use this contingency table. C Women Men 0.45 0.05 0.50 0.25 0.25 0.50 0.70 0.30 1.00 If a student has received a grade of C, what is the probability that the student is male? A) 0.05 B) 0.10 C) 0.30 D) 0.17 E) 0.50 Answer: B Explanation: P(Male | C) = = .10 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 239 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 82) At a college, 70 percent of the students are women and 50 percent of the students receive a grade of C. 25 percent of the students are neither female nor C students. Use this contingency table. C Women Men 0.45 0.05 0.50 0.25 0.25 0.50 0.70 0.30 1.00 If a student has received a grade of C, what is the probability that the student is female? A) 0.45 B) 0.90 C) 0.70 D) 0.64 E) 0.50 Answer: B Explanation: P(female | C) = = .90 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 240 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 83) Two percent of the customers of a store buy cigars. Half of the customers who buy cigars buy beer. 25 percent who buy beer buy cigars. Determine the probability that a customer buys beer. A) 0.25 B) 0.01 C) 0.04 D) 0.50 E) 0.005 Answer: C Explanation: Cigars P(Beer) = Beer .01 .03 .04 .01 .95 .96 = .02 .98 1.0 = .04 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 241 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 84) Two percent of the customers of a store buy cigars. Half of the customers who buy cigars buy beer. 25 percent who buy beer buy cigars. Determine the probability that a customer neither buys beer nor buys cigars. A) 0.98 B) 0.95 C) 0.75 D) 0.96 E) 0.50 Answer: B Explanation: Cigars Beer .01 .03 .04 .01 .95 .96 .02 .98 1.0 Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 85) An urn contains five white, three red, and four black balls. Three are drawn at random and not placed back into the urn. What is the probability that no ball is red? A) 0.7500 B) 0.0156 C) 0.2917 D) 0.4219 E) 0.3818 Answer: E Explanation: = .3818 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 242 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 86) The probability of event A occurring given that event B has already occurred is 0.61. The probability of both events occurring is 0.5. What is the probability of event B occurring? A) 0.305 B) 0.195 C) 0.390 D) 0.820 E) 0.500 Answer: D Explanation: P(B) = P(A ∩ B) / P(A | B) = .5/.61 = 0.81967 Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 87) What is the probability that any two people chosen at random were born on the same day of the week? A) 1/7 B) 1/49 C) 2/7 D) 2/49 Answer: A Explanation: Set up sample space: 72 = 49; same day: 7 sample space outcomes. Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 243 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 88) A letter is drawn from the alphabet of 26 letters. What is the probability that the letter drawn is a vowel? A) 5/26 B) 1/26 C) 4/26 D) 21/26 Answer: A Explanation: AEIOU; 5 vowels out of 26 letters. Difficulty: 1 Easy Topic: Probability and Events Learning Objective: 04-02 List the outcomes in a sample space and use the list to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 89) If A and B are independent events, P(A) = .2, and P(B) = .7, determine P(A ∪ B). A) 0.90 B) 0.14 C) 0.76 D) 0.50 E) 0.24 Answer: C Explanation: P(A ∪ B) = P(A) + P(B) - P(A ∩ B) P(A ∪ B) = (.7) + (.2) - (.7)(.2) = .76 Difficulty: 1 Easy Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 244 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 90) If events A and B are mutually exclusive, calculate P(A|B). A) Cannot be determined. B) 0 C) 1 D) 0.50 Answer: B Explanation: Mutually exclusive events have intersection = 0. Therefore, the conditional probability is also 0. Difficulty: 3 Hard Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 91) What is the probability of rolling a six with a fair die five times in a row? A) 1/6 B) 1/46,656 C) 1/7,776 D) 5/7,776 Answer: C Explanation: (1/6)5 = 1/7,776 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 245 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 92) If a product is made using five individual components, and P(product meets specifications) = P(E) = .98, what is the probability of an individual component meeting specifications, assuming that this probability is the same for all five components? A) 0.98 B) 0.996 C) 0.004 D) 0.02 E) 0.904 Answer: B Explanation: = .996 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 93) If P(A|B) = .2 and P(B) = .8, determine the intersection of events A and B. A) 0.20 B) 1.0 C) 0.25 D) 0.16 E) 0.60 Answer: D Explanation: (.2)(.8) = .16 Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 246 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 94) If P(A ∩ B ) = .3 and P(A | B) = .9, find P(B). A) 0.6 B) 0.3 C) 0.5 D) 0.27 E) 0.33 Answer: E Explanation: P(B) = = .333 Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 95) Employees of a local university have been classified according to gender and job type. Job Faculty (FA) Salaried Staff (SS) Hourly Staff (HS) Gender Male (M) Female (F) 110 10 30 50 60 40 If an employee is selected at random, what is the probability that the employee is male? A) .667 B) .367 C) .333 D) .500 E) .917 Answer: A Explanation: P(M) = = .667 Difficulty: 2 Medium Topic: Probability and Events Learning Objective: 04-02 List the outcomes in a sample space and use the list to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 247 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 96) Employees of a local university have been classified according to gender and job type. Job Faculty (FA) Salaried Staff (SS) Hourly Staff (HS) Gender Male (M) Female (F) 110 10 30 50 60 40 If an employee is selected at random, what is the probability that the employee is male and salaried staff? A) .15 B) .10 C) .38 D) .50 E) .85 Answer: B Explanation: P(M and SS) = = 0.10 Difficulty: 2 Medium Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 248 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 97) Employees of a local university have been classified according to gender and job type. Gender Male (M) Female (F) 110 10 30 50 60 40 Job Faculty (FA) Salaried Staff (SS) Hourly Staff (HS) If an employee is selected at random, what is the probability that the employee is female, given that the employee is a salaried member of the staff? A) .167 B) .500 C) .625 D) 267 E) .375 Answer: C Explanation: P(F | SS) = = = 0.625 Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 249 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 98) Employees of a local university have been classified according to gender and job type. Job Faculty (FA) Salaried Staff (SS) Hourly Staff (HS) Gender Male (M) Female (F) 110 10 30 50 60 40 If an employee is selected at random, what is the probability that the employee is female or works as a member of the faculty? A) 0.73 B) 0.08 C) 0.33 D) 0.70 E) 0.05 Answer: D Explanation: P(F ∪ FA) = + - = 0.70 Difficulty: 2 Medium Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 250 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 99) Employees of a local university have been classified according to gender and job type. Job Faculty (FA) Salaried Staff (SS) Hourly Staff (HS) Gender Male (M) Female (F) 110 10 30 50 60 40 If an employee is selected at random, what is the probability that the employee is female or works as an hourly staff member? A) 0.133 B) 0.533 C) 0.667 D) 0.400 E) 0.333 Answer: B Explanation: P(F ∪ HA) = + - = 0.533 Difficulty: 2 Medium Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 251 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 100) Employees of a local university have been classified according to gender and job type. Gender Male (M) Female (F) 110 10 30 50 60 40 Job Faculty (FA) Salaried Staff (SS) Hourly Staff (HS) If an employee is selected at random, what is the probability that the employee is a member of the hourly staff, given that the employee is female? A) 0.400 B) 0.133 C) 0.160 D) 0.053 E) 0.533 Answer: A Explanation: P(HS | F) = = = 0.400 Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 252 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 101) Employees of a local university have been classified according to gender and job type. Job Faculty (FA) Salaried Staff (SS) Hourly Staff (HS) Gender Male (M) Female (F) 110 10 30 50 60 40 If an employee is selected at random, what is the probability that the employee is a member of the faculty? A) 0.333 B) 0.600 C) 0.550 D) 0.400 E) 0.917 Answer: D Explanation: P(FA) = = .40 Difficulty: 2 Medium Topic: Probability and Events Learning Objective: 04-02 List the outcomes in a sample space and use the list to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 253 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 102) Employees of a local university have been classified according to gender and job type. Gender Male (M) Female (F) 110 10 30 50 60 40 Job Faculty (FA) Salaried Staff (SS) Hourly Staff (HS) Are gender and type of job mutually exclusive? A) Yes B) No Answer: B Explanation: No, gender and job type are not mutually exclusive. P(M) = = .667 P(FA) = P(M ∩ FA) = = 0.40 ≠0 Difficulty: 2 Medium Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Analyze AACSB: Analytical Thinking Accessibility: Keyboard Navigation 254 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 103) Employees of a local university have been classified according to gender and job type. Gender Male (M) Female (F) 110 10 30 50 60 40 Job Faculty (FA) Salaried Staff (SS) Hourly Staff (HS) Are gender and type of job statistically independent? A) Yes B) No Answer: B Explanation: No, gender is not independent of type of job. Select a category of gender (male) and a category of job status (faculty), if the two are independent of each other, then: P(M) = P(M | FA) Since P(M) = and P(M | FA) = = 0.667 = 0.9167 0.667 ≠ 0.9167 Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Analyze AACSB: Analytical Thinking Accessibility: Keyboard Navigation 255 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 104) Four employees who work as drive-through attendants at a local fast-food restaurant are being evaluated. As part of a quality improvement initiative and employee evaluation, these workers were observed over three days. One of the statistics collected was the proportion of time the employee forgot to include a napkin in the bag. Also recorded was the proportion of all dinners packed by each employee. Related information is given in the table. Worker Joe Jan Cheryl Clay Dinner Packed 25% 20% 20% 35% Dinner Packed With No Napkin 6% 2% 10% 4% What is the probability that Cheryl packed a given dinner and forgot to include a napkin? A) 0.20 B) 0.10 C) 0.45 D) 0.02 E) 0.30 Answer: D Explanation: P(Cheryl ∩ Forgot napkin) = (.20)(.10) = 0.02 Difficulty: 2 Medium Topic: Some Elementary Probability Rules; Conditional Probability and Independence Learning Objective: 04-03 Use elementary probability rules to compute probabilities.; 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 256 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 105) Four employees who work as drive-through attendants at a local fast-food restaurant are being evaluated. As part of a quality improvement initiative and employee evaluation, these workers were observed over three days. One of the statistics collected was the proportion of time the employee forgot to include a napkin in the bag. Also recorded was the proportion of all dinners packed by each employee. Related information is given in the table. Worker Joe Jan Cheryl Clay Dinner Packed 25% 20% 20% 35% Dinner Packed With No Napkin 6% 2% 10% 4% What is the probability that there is not a napkin included for a given order? A) 0.22 B) 0.24 C) 0.053 D) 0.015 E) 0.04 Answer: C Explanation: P(No Napkin) = (.25)(.06) + (.20)(.02) + (0.20)(.10) + (.35)(.04) = .053 Difficulty: 2 Medium Topic: Some Elementary Probability Rules; Conditional Probability and Independence Learning Objective: 04-03 Use elementary probability rules to compute probabilities.; 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 257 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 106) Four employees who work as drive-through attendants at a local fast-food restaurant are being evaluated. As part of a quality improvement initiative and employee evaluation, these workers were observed over three days. One of the statistics collected was the proportion of time the employee forgot to include a napkin in the bag. Also recorded was the proportion of all dinners packed by each employee. Related information is given in the table. Worker Joe Jan Cheryl Clay Dinner Packed 25% 20% 20% 35% Dinner Packed With No Napkin 6% 2% 10% 4% You just purchased a dinner and found that there is no napkin in your bag. What is the probability that Cheryl prepared your order? A) 0.377 B) 0.091 C) 0.083 D) 0.500 E) 0.020 Answer: A Explanation: P(Cheryl | No napkin) = = = .37774 Difficulty: 3 Hard Topic: Some Elementary Probability Rules; Conditional Probability and Independence Learning Objective: 04-03 Use elementary probability rules to compute probabilities.; 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 258 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 107) Four employees who work as drive-through attendants at a local fast-food restaurant are being evaluated. As part of a quality improvement initiative and employee evaluation, these workers were observed over three days. One of the statistics collected was the proportion of time the employee forgot to include a napkin in the bag. Also recorded was the proportion of all dinners packed by each employee. Related information is given in the table. Worker Joe Jan Cheryl Clay Dinner Packed 25% 20% 20% 35% Dinner Packed With No Napkin 6% 2% 10% 4% You just purchased a dinner and found that there is no napkin in your bag. What is the probability that Jan prepared your order? A) 0.200 B) 0.004 C) 0.018 D) 0.075 E) 0.100 Answer: D Explanation: P(Jan | No napkin) = = = .0755 Difficulty: 3 Hard Topic: Some Elementary Probability Rules; Conditional Probability and Independence Learning Objective: 04-03 Use elementary probability rules to compute probabilities.; 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 259 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 108) Joe is considering pursuing an MBA degree. He has applied to two different universities. The acceptance rate for applicants with similar qualifications is 25 percent for University A and 40 percent for University B. What is the probability that Joe will be accepted at both universities? A) 0.10 B) 0.25 C) 0.65 D) 0.625 E) 0.40 Answer: A Explanation: (.25)(.40) = 0.10 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 109) Joe is considering pursuing an MBA degree. He has applied to two different universities. The acceptance rate for applicants with similar qualifications is 25 percent for University A and 40 percent for University B. What is the probability that Joe will be accepted at University A and rejected at University B? A) 0.10 B) 0.85 C) 0.15 D) 0.25 E) 0.65 Answer: C Explanation: (.25)(.60) = 0.15 Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 260 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 110) Joe is considering pursuing an MBA degree. He has applied to two different universities. The acceptance rate for applicants with similar qualifications is 25 percent for University A and 40 percent for University B. What is the probability that Joe will not be accepted at either university? A) 0.75 B) 0.45 C) 0.90 D) 0.65 E) 0.60 Answer: B Explanation: (.75)(.60) = 0.45 Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 111) Joe is considering pursuing an MBA degree. He has applied to two different universities. The acceptance rate for applicants with similar qualifications is 25 percent for University A and 40 percent for University B. What is the probability that Joe will be accepted by at least one of the two universities? A) 0.25 B) 0.55 C) 0.10 D) 0.35 E) 0.40 Answer: B Explanation: 1 − (.75)(.60) = 0.55 Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 261 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 112) Joe is considering pursuing an MBA degree. He has applied to two different universities. The acceptance rate for applicants with similar qualifications is 25 percent for University A and 40 percent for University B. What is the probability that Joe will be accepted at one, and only one, university? A) 0.50 B) 0.10 C) 0.15 D) 0.30 E) 0.45 Answer: E Explanation: (.25)(.60) + (.75)(.40) = 0.45 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 113) Joe is considering pursuing an MBA degree. He has applied to two different universities. The acceptance rate for applicants with similar qualifications is 25 percent for University A and 40 percent for University B. Of the applicants with similar qualities, only 10 percent are accepted into both University A and University B. Is the acceptance decision at University A independent of the acceptance decision at University B? A) Yes B) No Answer: A Explanation: Yes, the two decisions are statistically independent. If the MBA acceptance decisions are independent at the two universities, then P(Accepted at A) = P(Accepted at A given Rejected at B). P(Accepted at A) = .25 = P(Accept at A | Reject at B) = = = .25 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Analyze AACSB: Analytical Thinking Accessibility: Keyboard Navigation 262 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 114) A report on high school graduation stated that 85 percent of high school students graduate. Suppose 3 high school students are randomly selected from different schools. What is the probability that all graduate? A) 0.85 B) 0.947 C) 0.614 D) 0.283 E) 0.003 Answer: C Explanation: (.85)(.85)(.85) = 0.614 Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 115) A report on high school graduation stated that 85 percent of high school students graduate. Suppose 3 high school students are randomly selected from different schools. What is the probability that exactly one of the three graduates? A) 0.019 B) 0.003 C) 0.614 D) 0.057 E) 0.850 Answer: D Explanation: (.85)(.15)(.15) + (.15)(.85)(.15) + (.15)(.15)(.85) = .057375 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 263 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 116) A report on high school graduation stated that 85 percent of high school students graduate. Suppose 3 high school students are randomly selected from different schools. What is the probability that none will graduate? A) 0.019 B) 0.003 C) 0.614 D) 0.057 E) 0.150 Answer: B Explanation: (.15)(.15)(.15) = .003375 Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 117) It is very common for a television series to draw a large audience for special events or for cliff-hanging story lines. Suppose that on one of these occasions, the special show drew viewers from 38.2 percent of all US TV households. Suppose that three TV households are randomly selected. What is the probability that all three households viewed this special show? A) 0.382 B) 0.127 C) 0.146 D) 0.726 E) 0.056 Answer: E Explanation: (.382)(.382)(.382) = .05574 Difficulty: 1 Easy Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 264 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 118) It is very common for a television series to draw a large audience for special events or for cliff-hanging story lines. Suppose that on one of these occasions, the special show drew viewers from 38.2 percent of all US TV households. Suppose that three TV households are randomly selected. What is the probability that none of the three households viewed this special show? A) 0.236 B) 0.056 C) 0.618 D) 0.382 E) 0.127 Answer: A Explanation: (.618)(.618)(.618) = .236 Difficulty: 1 Easy Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 119) It is very common for a television series to draw a large audience for special events or for cliff-hanging story lines. Suppose that on one of these occasions, the special show drew viewers from 38.2 percent of all US TV households. Suppose that three TV households are randomly selected. What is the probability that exactly one of the three households viewed the special show? A) 0.146 B) 0.084 C) 0.438 D) 0.382 E) 0.056 Answer: C Explanation: (.382)(.618)(.618) + (.618)(.382)(.618) + (.618)(.618)(.382) = .4376 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 265 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 120) A survey is made in a neighborhood of 80 voters. 65 are Democrats and 15 are Republicans. Of the Democrats, 35 are women, while 5 of the Republicans are women. If one subject from the group is randomly selected, find the probability the individual is either a woman or a Democrat. A) .538 B) .813 C) .500 D) .438 E) .875 Answer: E Explanation: P(W ∪ D) = P(W) + P(D) - P(W ∩ D) = (40/80) + (65/80) - (35/80) = .877 Difficulty: 2 Medium Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 121) A survey is made in a neighborhood of 80 voters. 65 are Democrats and 15 are Republicans. Of the Democrats, 35 are women, while 5 of the Republicans are women. If one subject from the group is randomly selected, find the probability the individual is a male Republican. A) .125 B) .500 C) .333 D) .667 E) .188 Answer: A Explanation: (10/80) = .125 Difficulty: 2 Medium Topic: Probability and Events Learning Objective: 04-02 List the outcomes in a sample space and use the list to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 266 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 122) A survey is made in a neighborhood of 80 voters. 65 are Democrats and 15 are Republicans. Of the Democrats, 35 are women, while 5 of the Republicans are women. If one subject from the group is randomly selected, find the probability the individual is a Democrat or a Republican. A) 0.50 B) 1.00 C) 0.813 D) 0.188 E) 0.152 Answer: B Explanation: All voters in the survey were either D or R. Therefore, the probability is 1. Difficulty: 1 Easy Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 123) New car owners were asked to evaluate their experiences in buying a new car during the past 12 months. In the survey, the owners indicated they were most satisfied with their experiences at the following three dealers (in no particular order): Subaru, Honda, and Buick. When ranking the dealers, how many outcomes are possible? A) 6 B) 9 C) 8 D) 10 E) 12 Answer: A Explanation: HSB, BHS, SHB, HBS, BSH, SBH Difficulty: 1 Easy Topic: Probability and Events Learning Objective: 04-02 List the outcomes in a sample space and use the list to compute probabilities. Bloom's: Understand AACSB: Analytical Thinking Accessibility: Keyboard Navigation 267 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 124) New car owners were asked to evaluate their experiences in buying a new car during the past 12 months. In the survey, the owners indicated they were most satisfied with their experiences at the following three dealers (in no particular order): Subaru, Honda, and Buick. Assuming that each set of rankings is equally likely, what is the probability that owners ranked Subaru first? A) 1/3 B) 1/6 C) 1/2 D) 5/6 E) 6/6 Answer: A Explanation: Sample spaces: HSB, BHS, SHB, HBS, BSH, SBH; 2/6, or 1/3 Difficulty: 1 Easy Topic: Probability and Events Learning Objective: 04-02 List the outcomes in a sample space and use the list to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 125) New car owners were asked to evaluate their experiences in buying a new car during the past 12 months. In the survey, the owners indicated they were most satisfied with their experiences at the following three dealers (in no particular order): Subaru, Honda, and Buick. Assuming that each set of rankings is equally likely, what is the probability that owners ranked Subaru third? A) 1/3 B) 1/6 C) 1/2 D) 5/6 E) 6/6 Answer: A Explanation: Sample spaces: HSB, BHS, SHB, HBS, BSH, SBH; 2/6, or 1/3 Difficulty: 1 Easy Topic: Probability and Events Learning Objective: 04-02 List the outcomes in a sample space and use the list to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 268 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 126) New car owners were asked to evaluate their experiences in buying a new car during the past 12 months. In the survey, the owners indicated they were most satisfied with their experiences at the following three dealers (in no particular order): Subaru, Honda, and Buick. Assuming that each set of rankings is equally likely, what is the probability that owners ranked Subaru first and Honda second? A) 1/3 B) 1/6 C) 1/2 D) 5/6 E) 6/6 Answer: B Explanation: HSB, BHS, SHB, HBS, BSH, SBH; 1/6 Difficulty: 1 Easy Topic: Probability and Events Learning Objective: 04-02 List the outcomes in a sample space and use the list to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 127) In a study of chain saw injuries, 57 percent involved arms or hands. If three different chain saw injury cases are randomly selected, find the probability that they all involved arms or hands. A) 0.570 B) 0.190 C) 0.185 D) 0.829 E) 0.325 Answer: C Explanation: (.57)(.57)(.57) = .185 Difficulty: 1 Easy Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 269 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 128) In a local survey, 100 citizens indicated their opinions on a revision to a local land-use plan. Of the 62 persons giving favorable responses, 40 were males. Of the 38 giving unfavorable responses, 15 were males. If one citizen is randomly selected, find the probability that person is female or has an unfavorable opinion. A) 0.83 B) 0.17 C) 0.51 D) 0.60 E) 0.61 Answer: D Explanation: P(F ∪ N) = P(F) + P(N) - P(F ∩ N) = .45 + .38 - .23 = .60 M F Y 40 22 62 N 15 23 38 65 45 100 Difficulty: 2 Medium Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 129) In a local survey, 100 citizens indicated their opinions on a revision to a local land-use plan. Of the 62 persons giving favorable responses, 40 were males. Of the 38 giving unfavorable responses, 15 were males. If one citizen is randomly selected, find the probability that person is male and has a favorable opinion. A) 0.40 B) 0.65 C) 0.62 D) 0.55 E) 0.25 Answer: A Explanation: 40/100 Difficulty: 1 Easy Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 270 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 130) In a local survey, 100 citizens indicated their opinions on a revision to a local land-use plan. Of the 62 persons giving favorable responses, 40 were males. Of the 38 giving unfavorable responses, 15 were males. If one citizen is randomly selected, find the probability that person has a favorable opinion or has an unfavorable opinion A) 0.00 B) 1.00 C) 0.62 D) 0.24 Answer: B Explanation: There are only the two types of responses, favorable and unfavorable. Thus, the probability = 1.0. Difficulty: 1 Easy Topic: Some Elementary Probability Rules Learning Objective: 04-03 Use elementary probability rules to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 131) A batch of 50 parts contains 6 defects. If two parts are drawn randomly, one at a time, and tested, what is the probability that both parts are defective? A) 0.014 B) 0.012 C) 0.120 D) 0.102 E) 0.222 Answer: B Explanation: (6/50)(5/49) = .012 Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 271 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 132) Suppose that you believe that the probability you will get a grade of B or better in Introduction to Finance is .6 and the probability that you will get a grade of B or better in Introduction to Accounting is .5. If these events are independent, what is the probability that you will receive a grade of B or better in both courses? A) 0.300 B) 0.833 C) 0.600 D) 0.500 E) 0.800 Answer: A Explanation: (.6)(.5) = .30 Difficulty: 1 Easy Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 272 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 133) In a major midwestern university, 55 percent of all undergraduates are female, 25 percent of all undergraduates belong to a Greek organization (fraternity or sorority), and 40 percent of all males belong to a Greek organization. What percentage of the undergraduates are female and in a Greek organization? A) 55% B) 25% C) 60% D) 7% E) 15% Answer: D Explanation: To complete the contingency table and answer the question on the intersection of female and Greek, since the initial information includes a conditional statement, you need to calculate the intersection of female and Greek: If P(Greek │ Male) = 40%. And 40% of .45 = .18. Then, Female & Greek = .25 − .18 = .07, or 7% Greek Non-Greek Female .07 .48 .55 Male .18 .27 .45 .25 .75 Difficulty: 3 Hard Topic: Some Elementary Probability Rules; Conditional Probability and Independence Learning Objective: 04-03 Use elementary probability rules to compute probabilities.; 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 273 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 134) In a major midwestern university, 55 percent of all undergraduates are female, 25 percent of all undergraduates belong to a Greek organization (fraternity or sorority), and 40 percent of all males belong to a Greek organization. What is the probability that one randomly selected undergraduate will be either a female or belong to a Greek organization? A) .73 B) .55 C) .80 D) .07 E) .87 Answer: A Explanation: To complete the contingency table and answer the question on the intersection of female or Greek, since the initial information includes a conditional statement, you need to calculate the intersection of male and Greek: If P(Greek │ Male) = 40%. And 40% of .45 = .18. Then, Female & Greek = .25 − .18 = .07, or 7%. P(Female) = 55%. P(Greek) = 25%. P(G ∪ F) = .55 + .25 − .07 = .73 Greek Non-Greek Fem ale .07 .48 .55 Mal e .18 .27 .45 .25 .75 Difficulty: 3 Hard Topic: Some Elementary Probability Rules; Conditional Probability and Independence Learning Objective: 04-03 Use elementary probability rules to compute probabilities.; 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 274 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 135) In a major midwestern university, 55 percent of all undergraduates are female, 25 percent of all undergraduates belong to a Greek organization (fraternity or sorority), and 40 percent of all males belong to a Greek organization. What is the probability that an undergraduate is in a Greek organization, given that the undergraduate is a female? A) .07 B) .55 C) .127 D) .039 E) 138 Answer: C Explanation: To complete the contingency table and answer the question on the intersection of female or Greek, since the initial information includes a conditional statement, you need to calculate the intersection of male and Greek: If P(Greek │ Male) = 40%. And 40% of .45 = .18. Then, Female & Greek = .25 − .18 = .07, or 7%. P(Female) = 55%. P(G|F) = .07/.55 = .127 Greek Non-Greek Fem ale .07 .48 .55 Mal e .18 .27 .45 .25 .75 Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 275 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 136) In a major midwestern university, 55 percent of all undergraduates are female, 25 percent of all undergraduates belong to a Greek organization (fraternity or sorority), and 40 percent of all males belong to a Greek organization. Are the events "female " and "belongs to a Greek organization" independent? A) Yes, independent. B) No, not independent. Answer: B Explanation: P(G|F) = .07/.55 = .127 ≠ P(G) Difficulty: 3 Hard Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Analyze AACSB: Analytical Thinking Accessibility: Keyboard Navigation 137) An ad agency is developing a campaign to promote a business opening in a new mall development. To develop an appropriate mailing list, they decide to purchase lists of credit card holders from MasterCard and American Express. Combining the lists, they find the following: 40 percent of the people on the list have only a MasterCard and 10 percent have only an American Express card. Another 20 percent hold both MasterCard and American Express. Finally, 30 percent of those on the list have neither card. Suppose a person on the list is known to have a MasterCard. What is the probability that person also has an American Express card? A) .20 B) .33 C) .18 D) .70 E) .90 Answer: B Explanation: P(AE|MC) = .20/.60 = .33 American Express No American Express MasterCard .20 .40 .60 No MasterCard .10 .30 .40 .30 .70 1.00 Difficulty: 2 Medium Topic: Conditional Probability and Independence Learning Objective: 04-04 Compute conditional probabilities and assess independence. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 276 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 138) Suppose that A1, A2, and B are events where A1 and A2 are mutually exclusive events and P(A1) = .7, P(A2) = .3, P(B│A1) = .2, P(B│A2) = .4. Find P(B). A) 0.60 B) 0.26 C) 0.21 D) 0.14 E) 0.28 Answer: B Explanation: P(B) = P(A1) × P(B│A1) + P(A2) × P(B│A2) = (.7)(.2) + (.3)(.4) = .26 Difficulty: 3 Hard Topic: Bayes' Theorem Learning Objective: 04-05 Use Bayes' Theorem to update prior probabilities to posterior probabilities. Bloom's: Understand AACSB: Analytical Thinking Accessibility: Keyboard Navigation 139) Suppose that A1, A2, and B are events where A1 and A2 are mutually exclusive events and P(A1) = .7, P(A2) = .3, P(B│A1) = .2, P(B│A2) = .4. Find P(A1│B). A) 0.12 B) 0.26 C) 0.21 D) 0.54 E) 0.28 Answer: D Explanation: P(A1│B) = P(A1∩B)/P(B) = .14/.26 = .54 Difficulty: 3 Hard Topic: Bayes' Theorem Learning Objective: 04-05 Use Bayes' Theorem to update prior probabilities to posterior probabilities. Bloom's: Understand AACSB: Analytical Thinking Accessibility: Keyboard Navigation 277 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 140) Suppose that A1, A2, and B are events where A1 and A2 are mutually exclusive events and P(A1) = .7, P(A2) = .3, P(B│A1) = .2, P(B│A2) = .4. Find P(A2│B). A) 0.12 B) 0.26 C) 0.21 D) 0.14 E) 0.46 Answer: E Explanation: P(A2│B) = P(A2∩B)/P(B) = .12/.26 = .46 Difficulty: 3 Hard Topic: Bayes' Theorem Learning Objective: 04-05 Use Bayes' Theorem to update prior probabilities to posterior probabilities. Bloom's: Understand AACSB: Analytical Thinking Accessibility: Keyboard Navigation 141) Suppose that 60 percent of a company's computer chips are manufactured in Factory A, while 40 percent are produced in Factory B [P(A) = .60 for a randomly selected chip]. The defect rates for the two factories are 35 percent for Factory A and 25 percent for Factory B. Suppose we now know that the randomly selected chip is defective. Find the probability that the defective chip comes from Factory A. Answer: .677 P(A│Defective) = P(A ∩ Defective)/[P(A) × P(Defective│A) + P(B) × P(Defective│B)] = (.6 × .35)/[(.6 × .35) + (.4 × .25)] = .677 Difficulty: 3 Hard Topic: Bayes' Theorem Learning Objective: 04-05 Use Bayes' Theorem to update prior probabilities to posterior probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 278 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 142) A television program director has 14 shows available for Monday night but can choose only 5 shows. How many different possible combinations are there? Answer: 2002 14!/5!9! Difficulty: 2 Medium Topic: Counting Rules Learning Objective: 04-06 Use some elementary counting rules to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 143) An auditing firm has developed a set of criteria for determining whether a particular account (and its balance) is in error. Historically, they know that of balances that were in error, 75 percent were regarded as unusual. Assume Company A shows a history of only 10 percent of the account balances being in error and it also shows that 25 percent of the account balances were unusual. If in an audit, a particular account balance appears unusual, what is the probability that it is in error for Company A? Answer: .30 P(Error) = .10 P(Unusual) = .25 P(Unusual│Error) = .75 P(Error│Unusual) for Company A = P(Unusual│Error) × P(Error)/P(Unusual) = (.75 × .10)/.25 = .30 Difficulty: 3 Hard Topic: Bayes' Theorem Learning Objective: 04-05 Use Bayes' Theorem to update prior probabilities to posterior probabilities. Bloom's: Understand AACSB: Analytical Thinking Accessibility: Keyboard Navigation 279 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 144) An auditing firm has developed a set of criteria for determining whether a particular account (and its balance) is in error. Historically, they know that of balances that were in error, 75 percent were regarded as unusual. Assume Company A shows a history of only 10 percent of the account balances being in error and it also shows that 25 percent of the account balances were unusual. What are the states of nature and the experimental outcomes? Answer: States of Nature are "Error in account balance" and "No error in account balance;" Experimental Outcomes are "Account balance appears unusual" and "Account balance does not appear unusual." Difficulty: 3 Hard Topic: Bayes' Theorem Learning Objective: 04-05 Use Bayes' Theorem to update prior probabilities to posterior probabilities. Bloom's: Understand AACSB: Analytical Thinking Accessibility: Keyboard Navigation 145) A worldwide personal products manufacturer is working on a new hair care product. In the past, 85 percent of new hair care products introduced by this company have become successful (15 percent have failed). Obviously, the marketing research department plays a large role in the introduction of any new product. Historically, 85 percent of the successful products have a favorable rating from marketing research studies and 20 percent of the unsuccessful products have favorable ratings. For the new hair care product, the marketing unit has issued a favorable rating. What is the probability that the new product will be successful? Answer: .96 P(Success) = P(S) = .85 P(Unsuccessful) = P(U) = .15 Event F = Favorable Event NF = Not favorable P(F│S) = .85 P(F│U) = .20 P(S│F) = (.85 × .85)/[(.85 × .85) + (.20 × .15)] = .96 Difficulty: 3 Hard Topic: Bayes' Theorem Learning Objective: 04-05 Use Bayes' Theorem to update prior probabilities to posterior probabilities. Bloom's: Understand AACSB: Analytical Thinking Accessibility: Keyboard Navigation 280 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 146) Suppose the probability that an individual has a particular medical condition is .10. Tests of an individual's DNA can determine whether they have this medical condition but with only an 85 percent accuracy rate (that is, if the condition is present, the probability that the DNA test will give a positive finding is .85). If the medical condition is not present, the probability of the DNA test saying the medical condition exists is 0.03. What is the probability that the medical condition is present if the DNA test comes back positive? Answer: .76 P(MC exists) = P(MC) = .10 P(MC doesn't exist) = P(NMC) = .90 Event D = DNA test positive Event ND = DNA test not positive P(D│MC) = .85 P(D│NMC) = .03 P(MC│D) = (.85 × .10)/[(.85 × .10) + (.03 × .9)] = .759 Difficulty: 3 Hard Topic: Bayes' Theorem Learning Objective: 04-05 Use Bayes' Theorem to update prior probabilities to posterior probabilities. Bloom's: Understand AACSB: Analytical Thinking Accessibility: Keyboard Navigation 281 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 147) Three companies produce all the potato chips used by vending machines in public areas in a midwestern state. Company A accounts for 70 percent of the chips, Company B 19 percent, and Company C 11 percent. The probability of the vending company getting an unfilled bag is 2 percent for Company A, 2 percent for Company B, and 4 percent for Company C. Suppose an unfilled bag is found. What is the probability that it came from Company A? Answer: .63 P(A) = .70 P(B) = .19 P(C) = .11 P(U│A) = .02 P(U│B) = .02 P(U│C) = .04 P(U) = P(A∩U) + P(B∩U) + P(C∩U) = .014 + .0038 + .0044 = .0222 P(A│U) = P(A∩U)/P(U) = .014/.0222 = .63 Difficulty: 3 Hard Topic: Bayes' Theorem Learning Objective: 04-05 Use Bayes' Theorem to update prior probabilities to posterior probabilities. Bloom's: Understand AACSB: Analytical Thinking Accessibility: Keyboard Navigation 282 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 148) Three companies produce all the potato chips used by vending machines in public areas in a midwestern state. Company A accounts for 70 percent of the chips, Company B 19 percent, and Company C 11 percent. The probability of the vending company getting an unfilled bag is 2 percent for Company A, 2 percent for Company B, and 4 percent for Company C. Suppose an unfilled bag is found. What is the probability that it came from Company B? Answer: .17 P(A) = .70 P(B) = .19 P(C) = .11 P(U│A) = .02 P(U│B) = .02 P(U│C) = .04 P(U) = P(A ∩ U) + P(B ∩ U) + P(C ∩ U) = .014 + .0038 + .0044 = .0222 P(B│U) = P(B ∩ U)/P(U) = .0038/.0222 = .17 Difficulty: 3 Hard Topic: Bayes' Theorem Learning Objective: 04-05 Use Bayes' Theorem to update prior probabilities to posterior probabilities. Bloom's: Understand AACSB: Analytical Thinking Accessibility: Keyboard Navigation 283 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 149) Three companies produce all the potato chips used by vending machines in public areas in a midwestern state. Company A accounts for 70 percent of the chips, Company B 19 percent, and Company C 11 percent. The probability of the vending company getting an unfilled bag is 2 percent for Company A, 2 percent for Company B, and 4 percent for Company C. Suppose an unfilled bag is found. What is the probability that it came from Company C? Answer: .20 P(A) = .70 P(B) = .19 P(C) = .11 P(U│A) = .02 P(U│B) = .02 P(U│C) = .04 P(U) = P(A ∩ U) + P(B ∩ U) + P(C ∩ U) = .014 + .0038 + .0044 = .0222 P(C│U) = P(C ∩ U)/P(U) = .0044/.0222 = .1982 Difficulty: 3 Hard Topic: Bayes' Theorem Learning Objective: 04-05 Use Bayes' Theorem to update prior probabilities to posterior probabilities. Bloom's: Understand AACSB: Analytical Thinking Accessibility: Keyboard Navigation 284 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 150) Every current applicant for a position in the marketing department of Company A is given a 10-question test on interpretation of findings from statistical analyses. Individuals are rated on three levels based on their scores: Excellent (9-10 correct), Average (5-8 correct), and Poor (fewer than 5 correct). Historically, the probability of an individual scoring Excellent = .38, Average = .52, and Poor = .10. Also, the company knows that 90 percent of applicants who score Excellent are offered a position, 75 percent of applicants who score Average are offered a position, and 35 percent of the applicants who score Poor are offered a position. What is the probability that an individual who is offered a position has an Excellent score? Answer: .446 P(E) = .38 P(A) = .52 P(P) = .10 P(O│E) = .90 P(O│A) = .75 P(O│P) = .35 P(O) = P(E ∩ O) + P(A ∩ O) + P(P ∩ O) = .342 + .39 + .035 = .767 P(E│O) = P(E ∩ O)/P(O) = .342/.767 = .446 Difficulty: 3 Hard Topic: Bayes' Theorem Learning Objective: 04-05 Use Bayes' Theorem to update prior probabilities to posterior probabilities. Bloom's: Understand AACSB: Analytical Thinking Accessibility: Keyboard Navigation 285 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 151) Every current applicant for a position in the marketing department of Company A is given a 10-question test on interpretation of findings from statistical analyses. Individuals are rated on three levels based on their scores: Excellent (9-10 correct), Average (5-8 correct), and Poor (fewer than 5 correct). Historically, the probability of an individual scoring Excellent = .38, Average = .52, and Poor = .10. Also, the company knows that 90 percent of applicants who score Excellent are offered a position, 75 percent of applicants who score Average are offered a position, and 35 percent of the applicants who score Poor are offered a position. What is the probability that an individual who is offered a position has an Average score? Answer: .508 P(E) = .38 P(A) = .52 P(P) = .10 P(O│E) = .90 P(O│A) = .75 P(O│P) = .35 P(O) = P(E∩O) + P(A ∩ O) + P(P ∩ O) = .342 + .39 + .035 = .767 P(A│O) = P(A ∩ O)/P(O) = .39/.767 = .508 Difficulty: 3 Hard Topic: Bayes' Theorem Learning Objective: 04-05 Use Bayes' Theorem to update prior probabilities to posterior probabilities. Bloom's: Understand AACSB: Analytical Thinking Accessibility: Keyboard Navigation 286 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 152) Every current applicant for a position in the marketing department of Company A is given a 10-question test on interpretation of findings from statistical analyses. Individuals are rated on three levels based on their scores: Excellent (9-10 correct), Average (5-8 correct), and Poor (fewer than 5 correct). Historically, the probability of an individual scoring Excellent = .38, Average = .52, and Poor = .10. Also, the company knows that 90 percent of applicants who score Excellent are offered a position, 75 percent of applicants who score Average are offered a position, and 35 percent of the applicants who score Poor are offered a position. What is the probability that an individual who is offered a position has a Poor score? Answer: .046 P(E) = .38 P(A) = .52 P(P) = .10 P(O│E) = .90 P(O│A) = .75 P(O│P) = .35 P(O) = P(E ∩ O) + P(A ∩ O) + P(P ∩ O) = .342 + .39 + .035 = .767 P(P│O) = P(P ∩ O)/P(O) = .035/.767 = .046 Difficulty: 3 Hard Topic: Bayes' Theorem Learning Objective: 04-05 Use Bayes' Theorem to update prior probabilities to posterior probabilities. Bloom's: Understand AACSB: Analytical Thinking Accessibility: Keyboard Navigation 287 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 1) The binomial experiment consists of n independent, identical trials, each of which results in either success or failure and is such that the probability of success on any trial is the same. Answer: TRUE Explanation: This is the definition of the binomial model. All of these characteristics need to be met. Difficulty: 1 Easy Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 2) A Poisson random variable is a continuous variable that can be used to describe the number of occurrences of an event over a specified interval of time or space. Answer: FALSE Explanation: Poisson random variables are not continuous, they are discrete. Difficulty: 1 Easy Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 3) A discrete random variable may assume a countable sequence or list. Answer: TRUE Explanation: It may assume a finite number of possible values or a countable sequence i.e. 1, 2, 3, 4, etc. Difficulty: 1 Easy Topic: Two Types of Random Variables Learning Objective: 06-01 Explain the difference between a discrete random variable and a continuous random variable. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 288 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 4) The variable Home Ownership can take on one of two values: 1 if the person living in the home owns the home and 0 if the person living in the home does not own the home. This is an example of a discrete random variable. Answer: TRUE Explanation: Because this variable has a finite number of possible values (either 0 or 1), it is a discrete random variable. Difficulty: 1 Easy Topic: Two Types of Random Variables Learning Objective: 06-01 Explain the difference between a discrete random variable and a continuous random variable. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 5) If the number of surface nonconformities on a specific size of a metal piece is the discrete random variable in question, then the appropriate probability distribution that can describe the probability of a specific size metal sheet containing 3 nonconformities is most likely given by the binomial distribution. Answer: FALSE Explanation: This example is a description of a hypergeometric distribution. Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 6) The mean of the binomial random variable is np(1 − p). Answer: FALSE Explanation: The mean of the binomial random variable is np. Difficulty: 1 Easy Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 289 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 7) In a binomial experiment, the results of one trial are dependent on the results of other trials. Answer: FALSE Explanation: One assumption of the binomial distribution is independence of trials. Difficulty: 1 Easy Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 8) In a binomial distribution, the random variable x is continuous. Answer: FALSE Explanation: The binomial distribution defines the random variable x as discrete. Difficulty: 1 Easy Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 9) The internal auditor for your company believes that 10 percent of their invoices contain errors. To check this theory, 20 invoices are randomly selected and 5 are found to have errors. Based on the above information, the claim of the auditor will be rejected. Answer: TRUE Explanation: Reject claim because P < .05. Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Analyze AACSB: Analytical Thinking Accessibility: Keyboard Navigation 10) The mean and the variance of a Poisson random variable are equal. Answer: TRUE Explanation: This is part of the definition of the Poisson random variable. Difficulty: 1 Easy Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 290 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 11) Depending on the mean of the Poisson distribution, the distribution can either be very skewed to the right or can be quite symmetrical. Answer: TRUE Explanation: The Poisson distribution is not skewed to the left. Difficulty: 1 Easy Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 12) For a discrete probability distribution, the value of p(x) for each value of x falls between −1 and 1. Answer: FALSE Explanation: Probability values, p(x), can only fall between 0 and 1. Difficulty: 1 Easy Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 13) The expected value of the discrete random variable x is the population mean. Answer: TRUE Explanation: In order to calculate the expected value, we multiply each value of x by its probability p(x) and then sum the resulting products over all possible values of x. Difficulty: 1 Easy Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 291 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 14) The standard deviation of a discrete random variable measures the spread of the population of all possible values of x. Answer: TRUE Explanation: The standard deviation can tell you how clustered or spread out the population of all possible values of x is. Difficulty: 1 Easy Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 15) The time (in seconds) it takes for an athlete to run 50 meters is an example of a continuous random variable. Answer: TRUE Explanation: The time it could take the athlete to run 50 meters could be any value between 0 and infinity. Difficulty: 2 Medium Topic: Two Types of Random Variables Learning Objective: 06-01 Explain the difference between a discrete random variable and a continuous random variable. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 16) The hypergeometric probability distribution can be approximated by the Poisson distribution. Answer: FALSE Explanation: The hypergeometric distribution is approximated by a binomial distribution. Difficulty: 1 Easy Topic: The Hypergeometric Distribution Learning Objective: 06-05 Use the hypergeometric distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 292 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 17) If the population size is at least 20 times larger than the sample size, a hypergeometric distribution can be approximated by the binomial distribution. Answer: TRUE Explanation: The population size needs to be much larger and the definition says 20 times larger than the sample size taken. Difficulty: 1 Easy Topic: The Hypergeometric Distribution Learning Objective: 06-05 Use the hypergeometric distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 18) In a hypergeometric probability distribution of a population of N items, r refers to the number of successes and N − r refers to the number of failures. Answer: TRUE Explanation: N refers to the number of items and r are the items that are successes. Therefore, by definition, N − r would be total − successes = failures. Difficulty: 1 Easy Topic: The Hypergeometric Distribution Learning Objective: 06-05 Use the hypergeometric distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 19) With two random variables x and y, a positive covariance says that as x increases, y tends to increase in a linear fashion. Answer: TRUE Explanation: This is shown on an x, y scatter plot; as one increases the other does as well. Difficulty: 1 Easy Topic: Joint Distributions and the Covariance Learning Objective: 06-06 Compute and understand the covariance between two random variables. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 293 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 20) A correlation coefficient is a unitless measure of the linear relationship between two random variables. Answer: TRUE Explanation: It can be positive or negative. Difficulty: 1 Easy Topic: Joint Distributions and the Covariance Learning Objective: 06-06 Compute and understand the covariance between two random variables. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 21) The property of expected values says if a and b are constants, and if x and y are random variables, then μ (ax +by) = aμx + bμy + 2ab. Answer: FALSE Explanation: The property of expected values does not include the value 2ab. Difficulty: 1 Easy Topic: Joint Distributions and the Covariance Learning Objective: 06-06 Compute and understand the covariance between two random variables. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 22) The random variable x has a hypergeometric distribution and the population contains 12 items. If you wanted to find the number of defects in a random sample of 3 selected items when the population contains 5 defects, identify the N, n, and r. A) N = 3, n = 12, r = 5 B) N = 5, n = 12, r = 2 C) N = 12, n = 5, r = 3 D) N = 12, n = 3, r = 5 Answer: D Explanation: In the hypergeometric distribution, N is the number of items in the population, r the number of successes, and n a random sample of the population N. Difficulty: 2 Medium Topic: The Hypergeometric Distribution Learning Objective: 06-05 Use the hypergeometric distribution to compute probabilities. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 294 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 23) A hypergeometric random variable x has a distribution that is approximated by a binomial distribution when A) the number of successes is larger than the number of failures in the population. B) a sample is selected from the population without replacement. C) the population is much larger (about 20 times larger) than the sample size. D) the sample size is half the size of the original population. Answer: C Explanation: This is by definition — much larger is 20 times larger. Difficulty: 1 Easy Topic: The Hypergeometric Distribution Learning Objective: 06-05 Use the hypergeometric distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 24) In the context of the hypergeometric distribution, r is A) the sample size. B) the number of items in the population that are successes. C) the number of items that are sampled without replacement. D) the number of items in the sample that are successes. Answer: B Explanation: N is the number of items and r is the number of those items that were successes. Difficulty: 1 Easy Topic: The Hypergeometric Distribution Learning Objective: 06-05 Use the hypergeometric distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 25) Which of the following is not a discrete random variable? A) the number of times a light changes red in a 10-minute cycle B) the number of minutes required to run 1 mile C) the number of defects in a sample selected from a population of 100 products D) the number of criminals found in a five-mile radius of a neighborhood Answer: B Explanation: It could take someone infinite number of minutes to finish the 1 mile. Difficulty: 2 Medium Topic: Two Types of Random Variables Learning Objective: 06-01 Explain the difference between a discrete random variable and a continuous random variable. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 295 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 26) A random variable A) is the result of a measurement. B) can only be discrete. C) assigns one and only one numeric value to each experimental outcome. D) is a binomial, Poisson, or hypergeometric variable. Answer: C Explanation: A random variable is countable. Difficulty: 1 Easy Topic: Two Types of Random Variables Learning Objective: 06-01 Explain the difference between a discrete random variable and a continuous random variable. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 27) A discrete probability distribution is expressed as a table, graph, or ________ that gives the probability associated with each possible value that the random variable can assume. A) binomial B) formula C) Poisson D) hypergeometric Answer: B Explanation: This distribution, no matter how it is displayed, will sum to 1. Difficulty: 1 Easy Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 296 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 28) Using the following probability distribution table of the random variable x, what is the probability of x = 3? X 0 1 2 3 P(X) 5/15 4/15 1/15 A) 3/15 B) 5/15 C) 1/15 D) 2/15 Answer: B Explanation: All values of P(X) need to sum to 1, so 5/15 + 4/15 + 1/15 = 10/15 means P(X = 3) = 5/15. Difficulty: 2 Medium Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 29) The probability distribution of a random variable that is defined to be the number of successes obtained in a random sample selected without replacement from a finite population of N elements that contains r successes and N − r failures is A) Poisson. B) binomial. C) hypergeometric. D) discrete. Answer: C Explanation: This is the definition of a hypergeometric distribution. The population must be 20 times larger than the sample size. Difficulty: 1 Easy Topic: The Hypergeometric Distribution Learning Objective: 06-05 Use the hypergeometric distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 297 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 30) The mean of a hypergeometric random variable is defined as A) n(r/N). B) N(r/n). C) npq. D) np. Answer: A Explanation: This is where N is the population size, n is the sample size and r is the number of successes. Difficulty: 1 Easy Topic: The Hypergeometric Distribution Learning Objective: 06-05 Use the hypergeometric distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 31) If p = .1 and n = 5, then the corresponding binomial distribution is ________. A) right skewed B) left skewed C) symmetric D) bimodal Answer: A Explanation: Most of the values for this binomial distribution are on the left-hand side of the graph. Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Analyze AACSB: Reflective Thinking Accessibility: Keyboard Navigation 32) If p = .5 and n = 4, then the corresponding binomial distribution is ________. A) right skewed B) left skewed C) symmetric D) bimodal Answer: C Explanation: It is similar to a bell curve. Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Analyze AACSB: Reflective Thinking Accessibility: Keyboard Navigation 298 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 33) The requirement that the probability of success remains constant from trial to trial is a property of the ________ distribution. A) binomial B) uniform C) normal D) Poisson Answer: A Explanation: Each trial is not affected by previous successes or failures. Difficulty: 1 Easy Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 34) If the number of surface nonconformities on a specific size of metal piece is the discrete random variable in question, then the appropriate probability distribution that can describe the probability of a specific size metal sheet containing 3 defects is given most likely by ________ distribution(s). A) the binomial B) the Poisson C) the hypergeometric D) both the binomial and Poisson Answer: C Explanation: In this case we can assume that the probability of a success is essentially constant from selection to selection. Difficulty: 2 Medium Topic: The Hypergeometric Distribution Learning Objective: 06-05 Use the hypergeometric distribution to compute probabilities. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 299 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 35) Which of the following distributions can be used to solve the following problem? The average number of cars arriving at a drive-through fast-food restaurant is 3 cars in 10 minutes. What is the probability that exactly four cars will arrive in a 5-minute interval? A) binomial B) Poisson C) both binomial and Poisson D) neither binomial nor Poisson Answer: B Explanation: A Poisson would be the best choice because it looks at the number of times an event occurs an interval of time or space. Difficulty: 3 Hard Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Analyze AACSB: Reflective Thinking Accessibility: Keyboard Navigation 36) The mean of the binomial distribution is equal to A) p. B) np. C) px(1 − p)n−x. D) (n)(p)(1 − p). E) (1 − p) Answer: B Explanation: Where n is the number of trials and p is the probability of success on each trial. Difficulty: 1 Easy Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 300 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 37) The number of ways to arrange x successes among n trials is equal to A) . B) . C) . D) . Answer: A Explanation: N is the number of trials in an experiment and x is the number of successes in that experiment. Difficulty: 1 Easy Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 38) Which of the following is a valid probability value for a discrete random variable? A) .2 B) 1.01 C) −.7 D) All of the choices are correct. Answer: A Explanation: The probability of a discrete random variable can only be between 0 and +1. Difficulty: 1 Easy Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 301 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 39) A total of 50 raffle tickets are sold for a contest to win a car. If you purchase one ticket, what are your odds against winning? A) 49 to 1 B) 50 to 1 C) .05 D) .01 Answer: A Explanation: Probability of losing = 1 − probability of winning = 1 − 1/50 = 49/50. Difficulty: 3 Hard Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 40) Which one of the following statements is not an assumption of the binomial distribution? A) Sampling is with replacement. B) The experiment consists of an identical trial. C) The probability of success remains constant from trial to trial. D) Trials are independent of each other. E) Each trial results in one of two mutually exclusive outcomes. Answer: A Explanation: All trials are independent and you do not replace once you have a success or failure. Difficulty: 1 Easy Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 302 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 41) The binomial distribution is characterized by situations that are analogous to A) drawing balls from an urn. B) coin tossing. C) counting defects on an item. D) measuring the length of an item. Answer: B Explanation: Binomial distributions assume a constant probability of success. Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 42) Two characteristics, or assumptions, of the Poisson distribution are that A) the probability of success remains constant from trial to trial, and the random variable of interest is continuous. B) the event occurring in any interval is independent of the event occurring in any other nonoverlapping interval, and the random variable of interest is continuous. C) the event occurring in any interval is independent of the event occurring in any other nonoverlapping interval, and the random variable of interest is discrete. D) the event occurring in any interval is dependent on the event occurring in any other nonoverlapping interval, and the random variable of interest is continuous. Answer: C Explanation: The random variable must be discrete, i.e., countable, and independent; a success in a previous trial does not dictate a success in a current trial. Difficulty: 1 Easy Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 303 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 43) The variable Employment Status, which can take either the value 1 for Employed or 0 for Unemployed, is an example of a ________ random variable. A) Poisson B) discrete C) hypergeometric D) continuous Answer: B Explanation: The variable is countable and is either one or the other; it cannot be both employed and unemployed at the same time. Difficulty: 1 Easy Topic: Two Types of Random Variables Learning Objective: 06-01 Explain the difference between a discrete random variable and a continuous random variable. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 44) If x is a binomial random variable, then the standard deviation of x is given by A) np. B) (npq)2. C) . D) npq. Answer: C Explanation: Where n is the number of trials, p is the number of successes and q is the number of failures. Difficulty: 1 Easy Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Remember AACSB: Analytical Thinking Accessibility: Keyboard Navigation 304 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 45) A random variable that is defined to be the total number of successes in n trials is a ________ random variable. A) binomial B) Poisson C) hypergeometric D) continuous Answer: A Explanation: This random variable also needs to be countable. Difficulty: 1 Easy Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 46) A discrete variable that can often be used to describe the number of occurrences of an event over a specified interval of time or space is a ________ random variable. A) Poisson B) discrete C) hypergeometric D) continuous Answer: A Explanation: Poisson distribution deals with successes during a time interval. Difficulty: 1 Easy Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 305 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 47) The requirement that the probability of success remains constant from trial to trial is a property of the ________ distribution. A) binomial B) Poisson C) hypergeometric D) continuous Answer: A Explanation: A previous success or failure does not dictate what will occur in the present trial. Difficulty: 1 Easy Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 48) The distribution whose mean is equal to its variance is the ________ distribution. A) binomial B) Poisson C) hypergeometric D) continuous Answer: B Explanation: This is the definition of a Poisson. Difficulty: 1 Easy Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 306 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 49) For a random variable X, the mean value of the squared deviations of its values from their expected value is called its ________. A) standard deviation B) mean C) probability D) variance Answer: D Explanation: This can then be used to find the standard deviation, which is the positive square root of the variance. Difficulty: 2 Medium Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Understand AACSB: Reflective Thinking Accessibility: Keyboard Navigation 50) When p = .5, the binomial distribution will ________ be symmetric. A) always B) sometimes C) never Answer: A Explanation: This looks similar to a normal distribution. Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Understand AACSB: Analytical Thinking Accessibility: Keyboard Navigation 307 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 51) Which of the following statements about the binomial distribution is not correct? A) Each trial results in a success or failure. B) Trials are independent of each other. C) The probability of success remains constant from trial to trial. D) The random variable of interest is continuous. E) The experiment consists of n identical trials. Answer: D Explanation: The random variable of interest needs to be discrete. Difficulty: 1 Easy Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Remember AACSB: Reflective Thinking Accessibility: Keyboard Navigation 52) If n = 15 and p = .4, then the standard deviation of the binomial distribution is A) 9. B) 6. C) 3.6. D) 1.897. E) 2.449. Answer: D Explanation: Standard deviation = = = = 1.897 Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 53) The equation for the variance of the binomial distribution is given by A) px(1 − p)n−x. B) np. C) np(1 − p). D) . Answer: C Explanation: Where n is the number of trials and p is the probability of success. Difficulty: 1 Easy Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Remember AACSB: Analytical Thinking Accessibility: Keyboard Navigation 308 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 54) The Securities and Exchange Commission has determined that the number of companies listed on the NYSE declaring bankruptcy is approximately a Poisson distribution with a mean of 2.6 per month. Find the probability that exactly 4 bankruptcies occur next month. A) .8774 B) .1414 C) .7736 D) .2640 Answer: B Explanation: P(4) = e−2.6(2.6)4/4! (e = 2.71828) Difficulty: 3 Hard Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 55) The Securities and Exchange Commission has determined that the number of companies listed on the NYSE declaring bankruptcy is approximately a Poisson distribution with a mean of 2.6 per month. Find the probability that more than 1 bankruptcy occurs next month. A) .1931 B) .9257 C) .7326 D) .4816 E) .2674 Answer: C Explanation: P(1) = e−2.6(2.6)1/1! (e = 2.71828) Difficulty: 3 Hard Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 309 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 56) The Securities and Exchange Commission has determined that the number of companies listed on the NYSE declaring bankruptcy is approximately a Poisson distribution with a mean of 2.6 per month. Find the probability that no more than one bankruptcy occurs next month. A) .1931 B) .9257 C) .7326 D) .0742 E) .2674 Answer: E Explanation: P(X = 0 or X = 1) = e−2.6(2.6)0/0! + e−2.6(2.6)1/1! (e = 2.71828) Difficulty: 3 Hard Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 57) A fair die is rolled 10 times. What is the probability that an odd number (1, 3, or 5) will occur fewer than 3 times? A) .0547 B) .1172 C) .1550 D) .7752 E) .8450 Answer: A Explanation: ΣP(X) = n!/[x!(n − x)!] × px(1 − p)n−x, for x = 1, 3, 5; or look up in binomial table where x = 1 or 3 or 5 when p = .5 and n = 10. Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 310 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 58) A fair die is rolled 10 times. What is the probability that an even number (2, 4, or 6) will occur between 2 and 4 times inclusive? A) .6123 B) .1709 C) .1611 D) .3662 E) .3223 Answer: D Explanation: ΣP(X) = n!/[x!(n − x)!] × px(1 − p)n−x, for x = 2, 4, 6; or look up in binomial table, where x = 2 or 4 or 6 when p = .5 and n = 10. Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 59) A fair die is rolled 10 times. What is the average number of even number outcomes? A) 3 B) 4 C) 5 D) 6 E) 7 Answer: C Explanation: Binomial mean = μ = np = 10(.5) = 5 Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 311 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 60) A fair die is rolled 36 times. What is the standard deviation of the even number (2, 4, or 6) outcomes? A) 18 B) 9 C) 4.243 D) 3 E) 1.732 Answer: D Explanation: Binomial standard deviation = σ = = = =3 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 61) The manager of the local grocery store has determined that, on average, 4 customers use the service desk every half-hour. Assume that the number of customers using the service desk has a Poisson distribution. What is the probability that during a randomly selected half-hour period, exactly 2 customers use the service desk? A) .1483 B) .0916 C) .1465 D) .9084 E) .7619 Answer: C Explanation: P(2) = e−4(4)2/2! (e = 2.71828) Difficulty: 3 Hard Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 312 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 62) The manager of the local grocery store has determined that, on average, 4 customers use the service desk every half-hour. Assume that the number of customers using the service desk has a Poisson distribution. What is the probability that during a randomly selected half-hour period, no more than 2 customers use the service desk? A) .2381 B) .1465 C) .7619 D) .9084 E) .0916 Answer: A Explanation: P(x < 3) = Σ e−μ(μ)x/x!, for x = 0, 1, 2 (e = 2.71828) Difficulty: 3 Hard Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 63) The probability that a given computer chip will fail is .02. Find the probability that of 5 delivered chips, exactly 2 chips will fail. A) .9962 B) .0999 C) .0038 D) .0000 Answer: C Explanation: P(X) = n!/[x!(n − x)!] × px(1 − p)n−x, for x = 2, n = 5, p = .02 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 313 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 64) According to a survey of adults, 64 percent have money in a bank savings account. If we were to survey 50 randomly selected adults, find the mean number of adults who would have bank savings accounts. A) 12 B) 22 C) 32 D) 42 Answer: C Explanation: Mean = np = 50(.64) = 32 Difficulty: 3 Hard Topic: Discrete Probability Distributions Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 65) In the most recent election, 19 percent of all eligible college students voted. If a random sample of 20 students were surveyed, find the probability that exactly half voted in the election. A) .0000 B) .0014 C) .0004 D) .0017 Answer: B Explanation: P(X) = n!/[x!(n − x)!] × px(1 − p)n−x, for x = 10, when p = .19 and n = 20. Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 314 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 66) In the most recent election, 19 percent of all eligible college students voted. If a random sample of 20 students were surveyed, find the probability that none of the students voted. A) .0000 B) .0014 C) .0148 D) .9852 Answer: C Explanation: P(X) = n!/[x!(n − x)!] × px(1 − p)n−x, for x = 0 when p = .19 and n = 20. Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 67) Of all individual tax returns, 37 percent include errors made by the taxpayer. If IRS examiners are assigned randomly selected returns in batches of 12, find the mean and standard deviation for the number of erroneous returns per batch. A) μ = 2.80, σ = 1.67 B) μ = 4.44, σ = 1.67 C) μ = 4.44, σ = 2.80 D) μ = 7.56, σ = 2.80 Answer: B Explanation: Mean = np = 12(.37) = 4.44 Standard Deviation = = = 1.67 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 315 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 68) In a study conducted for the state Department of Education, 30 percent of the teachers who left teaching did so because they were laid off. Assume that we randomly select 10 teachers who have recently left their profession. Find the probability that exactly 4 of them were laid off. A) .6496 B) .8497 C) .2001 D) .1503 Answer: C Explanation: P(X) = n!/[x!(n − x)!] × px(1 − p)n−x, for x = 4, when p = .3 and n = 10 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 69) An appliance manufacturer gives a warranty and 95 percent of its appliances do not require repair before the warranty expires. An organization buys 10 of these appliances. Calculate an interval that contains 95.44 percent of all the appliances that will not require repair. A) [8.12, 10.88] B) [7.43, 11.57] C) [8.81, 10.19] D) [8.55, 10.45] Answer: A Explanation: μ = np = 10(.95) = 9.5 σ= = = .6892 95.44% is a 2-standard-deviation interval: [μ ± 2σ] = [9.5 ± 2(.6892)] = [8.12, 10.88] Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 316 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 70) A manufacturer tested a sample of semiconductor chips and found that 35 were defective and 190 were good. If additional tests are to be conducted with random samples of 160 semiconductor chips, find the mean for the number of defects in these groups of 160 (rounded to the nearest whole number). A) 56 B) 35 C) 29 D) 25 Answer: D Explanation: Sample size = 35 + 190 = 225 p = 35/225 = .156 Mean of 160 groups = 160(.156) = 24.96, rounded to 25 Difficulty: 3 Hard Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 71) A study conducted by a local university found that 25 percent of college freshmen support increased spending on environmental issues. If 6 college freshmen are randomly selected, find the probability that fewer than 4 support increased spending on environmental issues. A) .0330 B) .0046 C) .9624 D) .9954 Answer: C Explanation: Σ P(X) = n!/[x!(n − x)!] × px(1 − p)n−x, for x = 0, 1, 2, 3 when p = .25 and n = 6. Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 317 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 72) A study conducted by a local university found that 25 percent of college freshmen support increased spending on environmental issues. If 6 college freshmen are randomly selected, find the probability that exactly 3 support increased spending on environmental issues. A) .8306 B) .1318 C) .0376 D) .9624 Answer: B Explanation: P(X) = n!/[x!(n − x)!] × px(1 − p)n−x, for x = 3 when p = .25 and n = 6. Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 73) A study conducted by a local university found that 25 percent of college freshmen support increased spending on environmental issues. If 6 college freshmen are randomly selected, find the probability that only 1 supports increased spending on environmental issues. A) .3559 B) .1780 C) .3560 D) .5339 Answer: C Explanation: P(X) = n!/[x!(n − x)!] × px(1 − p)n−x, for x = 1 when p = .25 and n = 6. Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 318 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 74) A multiple-choice test has 30 questions and each one has five possible answers, of which only one is correct. If all answers were guesses, find the probability of getting exactly four correct answers. A) .1227 B) .1325 C) .0604 D) .0374 Answer: B Explanation: Probability of getting question correct = .2. Four successes in 30 trials. Treat as a binomial. P(X) = n!/[x!(n − x)!] × px(1 − p)n−x, for x = 4, when p = .20 and n = 30. Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 75) The J.O. Supplies Company buys calculators from a non-U.S. supplier. The probability of a defective calculator is 10 percent. If 3 calculators are selected at random, what is the probability that one of the calculators will be defective? A) .9720 B) .0280 C) .2430 D) .7290 Answer: C Explanation: = .243 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 319 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 76) The J.O. Supplies Company buys calculators from a non-U.S. supplier. The probability of a defective calculator is 10 percent. If 10 calculators are selected at random, what is the probability that 3 or more of the calculators will be defective? A) .0702 B) .0574 C) .9298 D) .0128 Answer: A Explanation: P(X ≥ 3) = 1 − P(X ≤ 2) = 1 − .9298 = .0702 Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 77) The J.O. Supplies Company buys calculators from a non-U.S. supplier. The probability of a defective calculator is 10 percent. If 100 calculators are selected at random, what is the expected number of defectives? A) 9 B) 90 C) 10 D) 95 Answer: C Explanation: E[X] = μx = (.10)(100) = 10 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 320 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 78) The J.O. Supplies Company buys calculators from a non-U.S. supplier. The probability of a defective calculator is 10 percent. If 100 calculators are selected at random, what is the standard deviation of the number of defective calculators? A) 9.00 B) 3.17 C) 9.49 D) 3.00 Answer: D Explanation: = =3 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 79) Historical data show that the average number of patient arrivals at the intensive care unit of General Hospital is 3 patients every two hours. Assume that the patient arrivals are distributed according to a Poisson distribution. Determine the probability of 6 patients arriving in a fivehour period. A) .136 B) .109 C) .246 D) .001 Answer: A Explanation: P(X = 6) = = .1359 Difficulty: 2 Medium Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 321 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 80) Historical data show that the average number of patient arrivals at the intensive care unit of General Hospital is 3 patients every 2 hours. Assume that the patient arrivals are distributed according to a Poisson distribution. Determine the probability of at least 4 but no more than 8 patients arriving in a three-hour period. A) .3813 B) .5711 C) .4276 D) .7861 E) .6174 Answer: E Explanation: P(4 ≤ X ≤ 8) = P(X = 8) + P(X = 7) + P(X = 6) + P(X = 5) + P(X = 4) = (.0463) + (.0824) + (.1281) + (.1708) + (.1898) = .6174 Difficulty: 2 Medium Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 81) The probability distribution of X is X 3 4 5 6 P(X) 1/8 1/8 3/8 3/8 What is the expected value of X? A) 1.0 B) 5.0 C) 2.25 D) 2.24 Answer: B Explanation: E[X] = 3 +4 +5 +6 = = 5.0 Difficulty: 2 Medium Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 322 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 82) The probability distribution of X is X 3 4 5 6 P(X) 1/8 1/8 3/8 3/8 What is the variance of X? A) 1.0 B) 5.0 C) 2.25 D) 2.24 Answer: A Explanation: E[X] = 3 = +4 +5 + +6 = + = 5.0 + =1 Difficulty: 2 Medium Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 323 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 83) Assume the number of trucks passing an intersection has a Poisson distribution with a mean of 5 trucks per minute. What is the probability of 0 or 1 trucks in one minute? A) .0404 B) .0337 C) .9596 D) .0067 Answer: A Explanation: + = .0404 Difficulty: 2 Medium Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 84) A vaccine is 95 percent effective. What is the probability that it is not effective for 1 and only 1 individual out of 20 individuals? A) .2642 B) .6415 C) .3584 D) .3774 Answer: D Explanation: (20)(.95)19(.05)1 = .3774 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 324 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 85) A vaccine is 95 percent effective. What is the probability that it is not effective for more than 1 out of 20 individuals? A) .7359 B) .2641 C) .6415 D) .3773 Answer: C Explanation: P(X ≥ 2) = 1 − [P(X = 0) + p(X = 1)] = 1 − [.3585 + .3774] = .2641 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 86) If the probability of a success on a single trial is .2, what is the probability of obtaining 3 successes in 10 trials if the number of successes is binomial? A) .1209 B) .6778 C) .1208 D) .2013 Answer: D Explanation: = .2013 Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 325 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 87) The number of calls coming into a call center follows a Poisson distribution with a mean of 120 calls per hour. What is the probability of no calls in a one-minute interval? A) 0 B) .1353 C) .4060 D) .3679 Answer: B Explanation: P(X = 0) = = = .1353 Difficulty: 3 Hard Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 88) If x is a Poisson random variable with a mean of 10, what is the probability that x is greater than 6? A) .9329 B) .1301 C) .8698 D) .0631 Answer: C Explanation: P(X ≥ 7) = 1 − P(X ≤ 6) = 1 − (.1302) = .8698 Difficulty: 3 Hard Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 326 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 89) Three candidates run for different offices in different cities. Each has a one in three chance of being elected in his/her city. What is the probability that at least one of them will be elected? A) .4444 B) .7037 C) .3300 D) .6670 Answer: B Explanation: P(X ≥ 1) = 1 − P(X = 0) P(X = 0) = =1− = = P(X ≥ 1) = .7037 Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 90) A test has 6 multiple-choice questions, each with 4 choices. What is the probability of guessing 5 or more questions correctly? A) .0044 B) .0002 C) .9954 D) .0046 Answer: D Explanation: P(X ≥ 5) = P(X = 5) + P(X = 6) = (.0044) + (.0002) = .0046 Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 327 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 91) If x is a Poisson random variable with a mean of 10, what is the probability that x is greater than or equal to 2? A) .9972 B) .0028 C) .9995 D) .0005 Answer: C Explanation: P(X ≥ 2) = 1 − [P(X = 0) + P(X = 1)] = 1 − (0 + .0005) = .9995 Difficulty: 3 Hard Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 92) If x is a Poisson random variable with a mean of 10, what is the probability that x is equal to 8? A) .1126 B) .2202 C) .3328 D) .7797 Answer: A Explanation: P(X = 8) = = .1126 Difficulty: 3 Hard Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 328 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 93) Twenty coins are tossed. What is the probability of getting exactly 10 heads? A) .4119 B) .5881 C) .5000 D) .1762 Answer: D Explanation: P(X = 10) = = .1762 Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 94) Determine the probability that a 3 will appear twice, if a single fair die is rolled 10 times. A) .7752 B) .2907 C) .1550 D) .4845 Answer: B Explanation: P(X = 2) = = .2907 Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 329 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 95) During off-hours, cars arrive at a tollbooth on the East-West toll road at an average rate of .5 cars per minute. The arrivals are distributed according to a Poisson distribution. What is the probability that during the next minute, three cars will arrive? A) .9856 B) .3033 C) .0126 D) .8956 Answer: C Explanation: P(X = 3) = = = .0126 Difficulty: 2 Medium Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 96) During off-hours, cars arrive at a tollbooth on the East-West toll road at an average rate of .5 cars per minute. The arrivals are distributed according to a Poisson distribution. What is the probability that during the next five minutes, three cars will arrive? A) .2138 B) .5438 C) .0126 D) .0002 Answer: A Explanation: P(X = 3) = = = .2138 Difficulty: 2 Medium Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 330 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 97) For a binomial process, the probability of success is 40 percent and the number of trials is 5. Find the expected value. A) 5.0 B) 1.2 C) 2.0 D) 1.1 Answer: C Explanation: E[X] = (5)(.40) = 2 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 98) For a binomial process, the probability of success is 40 percent and the number of trials is 5. Find the variance. A) 5.0 B) 1.2 C) 2.0 D) 1.1 Answer: B Explanation: σ2x = (5)(.4)(.6) = 1.2 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 331 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 99) For a binomial process, the probability of success is 40 percent and the number of trials is 5. Find the standard deviation. A) 5.0 B) 1.2 C) 2.0 D) 1.1 Answer: D Explanation: = = 1.0954 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 100) For a binomial process, the probability of success is 40 percent and the number of trials is 5. Find P(X ≤ 1). A) .2592 B) .6630 C) .0778 D) .3370 Answer: D Explanation: P(X ≤ 1) = P(X = 0) + P(X = 1) = (.0778) + (.2592) = .337 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 332 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 101) For a binomial process, the probability of success is 40 percent and the number of trials is 5. Find P(X > 4). A) .0102 B) .0778 C) .0870 D) .9898 Answer: A Explanation: P(X = 5) = (.4)5 = .0102 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 102) Consider a Poisson distribution with an average of 3 customers per minute at the local grocery store. Determine the expected number of customer arrivals for a five-minute period. A) 15 B) 3 C) 243 D) 125 Answer: A Explanation: μ = (3)(5) = 15 Difficulty: 3 Hard Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 333 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 103) Consider a Poisson distribution with an average of 3 customers per minute at the local grocery store. If X = the number of arrivals per minute, find the expected value of X. A) 3 B) 9 C) 1.5 D) 1.7 Answer: A Explanation: The expected value of X would be the average in the minute, or 3. Difficulty: 3 Hard Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 104) Consider a Poisson distribution with an average of 3 customers per minute at the local grocery store. If X = the number of arrivals per minute, find the variance of X. A) 3 B) 9 C) 1.5 D) 1.7 Answer: A Explanation: =μ=3 Difficulty: 3 Hard Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 334 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 105) Consider a Poisson distribution with an average of 4 customers per minute at the local grocery store. If X = the number of arrivals per minute, find the standard deviation of X. A) 2 B) 4 C) 16 D) 1.5 Answer: A Explanation: σx = = 2.00 Difficulty: 3 Hard Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 106) Consider a Poisson distribution with an average of 3 customers per minute at the local grocery store. If X = the number of arrivals per minute, find the probability of 10 customers or fewer arriving within a minute. A) .9998 B) .9990 C) .0008 D) .0002 Answer: A Explanation: P(X ≤ 10) = 1 − P(X ≥ 11) = 1 − .0002 = .9998 Difficulty: 2 Medium Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 335 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 107) Consider a Poisson distribution with an average of 3 customers per minute at the local grocery store. If X = the number of arrivals per minute, find the probability of more than 7 customers arriving within a minute. A) .0216 B) .0081 C) .9881 D) .0118 Answer: D Explanation: P(X ≥ 8) = .0081 + .0027 + .0008 + .0002 = .0118 Difficulty: 2 Medium Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 108) Consider a Poisson distribution with an average of 3 customers per minute at the local grocery store. If X = the number of arrivals per minute, find the probability of 3 customers arriving within a minute. A) 1.00 B) .4232 C) .2240 D) .3734 Answer: C Explanation: P(X = 3) = = = .224 Difficulty: 2 Medium Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 336 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 109) One die is thrown. What is the expected value of the number of dots on the top face of the die? A) 1.0 B) 3.5 C) 4.0 D) 3.0 Answer: B Explanation: E[X] = 1 +2 +3 +4 +5 +6 Difficulty: 2 Medium Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 110) X has the following probability distribution. X P(X) −2 0.2 −1 0.2 9 0.2 1 0.2 2 0.2 Compute the expected value of X. A) 1.3 B) 1.0 C) 2.4 D) 1.8 Answer: D Explanation: E[X] = (−2)(.2) + (−1)(.2) + (1)(.2) + (2)(.2) + (9)(.2) = 1.8 Difficulty: 2 Medium Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 337 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 111) X has the following probability distribution P(X). X P(X) 1 0.1 2 0.5 3 0.2 4 0.2 Compute the expected value of X. A) 2.5 B) 1.0 C) 1.6 D) .6 Answer: A Explanation: E[X] = (1)(.1) + (2)(.5) + (3)(.2) + (4)(.2) = 2.5 Difficulty: 2 Medium Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 112) X has the following probability distribution P(X). X P(X) 1 0.1 2 0.5 3 0.2 4 0.2 Compute the variance value of X. A) 1.58 B) .955 C) .850 D) .625 Answer: C Explanation: E[X] = (1)(.1) + (2)(.5) + (3)(.2) + (4)(.2) = 2.5 σ2x = (.1) + (.5) + (.2) + (.2) = .85 Difficulty: 2 Medium Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 338 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 113) Historical data for a local manufacturing company show that the average number of defects per product produced is 2. In addition, the number of defects per unit is distributed according to a Poisson distribution. What is the probability that there will be a total of 7 defects on four units? A) .6063 B) .0902 C) .0034 D) .1396 Answer: D Explanation: P(X = 7) = = = .1396 Difficulty: 2 Medium Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 114) Historical data for a local manufacturing company show that the average number of defects per product produced is 2. In addition, the number of defects per unit is distributed according to a Poisson distribution. A batch has just been completed. What is the probability that the first three units manufactured in this batch will contain at least a total of 4 defects? A) .8488 B) .7149 C) .1512 D) .2851 Answer: A Explanation: P(X ≥ 4) = 1 − [P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3)] = 1 − (.0025 + .0149 + .0446 + .0892) = .8488 Difficulty: 2 Medium Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 339 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 115) Historical data for a local manufacturing company show that the average number of defects per product produced is 2. In addition, the number of defects per unit is distributed according to a Poisson distribution. Determine the standard deviation of the number of defects for 32 units. A) 2 B) 32 C) 64 D) 8 Answer: D Explanation: = =8 Difficulty: 1 Easy Topic: The Poisson Distribution Learning Objective: 06-04 Use the Poisson distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 116) Consider the experiment of tossing a fair coin three times and observing the number of heads that result (X = number of heads). Determine the expected number of heads. A) 1.5 B) 1.0 C) 2.0 D) 1.1 Answer: A Explanation: E[X] = =0 + (1) + (2) + (3) = 1.5 Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 340 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 117) Consider the experiment of tossing a fair coin three times and observing the number of heads that result (X = number of heads). What is the variance for this distribution? A) 1.5 B) 1.22 C) .75 D) .87 Answer: C Explanation: E[X] = =0 = + (1) + (2) + + (3) + = 1.5 + = .75 Difficulty: 3 Hard Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 118) Consider the experiment of tossing a fair coin three times and observing the number of heads that result (X = number of heads). What is the standard deviation for this distribution? A) 1.5 B) 1.22 C) .75 D) .87 Answer: D Explanation: E[X] = = =0 + (1) + + (2) + (3) + = 1.5 + = .75 = = .866 Difficulty: 3 Hard Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 341 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 119) If you were asked to play a game in which you tossed a fair coin three times and were given $2 for every head you threw, how much would you expect to win on average? A) $3 B) $2 C) $6 D) $9 Answer: A Explanation: Expected return = 0 + ($2)(1) + ($2)(2) + ($2)(3) = 3.0 Difficulty: 3 Hard Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 120) A pharmaceutical company has determined that if a new cholesterol-reducing drug is manufactured and introduced to the market, the following probability distribution will describe the contribution of this drug to their profits during the next six months. Profit Contribution −$3,000,000 (negative profit) $5,000,000 $2,000,000 Probability of Profit Contribution 0.20 0.50 0.30 The company management has decided to market this product if the expected contribution to profit for the next six months is more than $1,000,000. Based on the information given above, should the company begin manufacturing the new drug? Explain your answer. A) Yes, begin manufacturing. B) No, do not begin manufacturing. Answer: A Explanation: μx = .2(−$3,000,000) + .5($5,000,000) + .3($2,000,000) = $2,500,000 $2,500,000 > $1,000,000 Difficulty: 2 Medium Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 342 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 121) According to data from the state blood program, 40 percent of all individuals have group A blood. If six individuals give blood, find the probability that none of the individuals has group A blood. A) .0041 B) .0410 C) .4000 D) .0467 Answer: D Explanation: P(x = 0) = .0467 Difficulty: 1 Easy Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 122) According to data from the state blood program, 40 percent of all individuals have group A blood. If six individuals give blood, find the probability that exactly three of the individuals have group A blood. A) .5443 B) .2765 C) .1792 D) .0041 Answer: B Explanation: P(x = 3) = .2765 Difficulty: 1 Easy Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 343 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 123) According to data from the state blood program, 40 percent of all individuals have group A blood. If six individuals give blood, find the probability that at least 3 of the individuals have group A blood. A) .8208 B) .5443 C) .4557 D) .1792 Answer: C Explanation: P(x ≥ 3) = p(x = 3) + p(x = 4) + p(x = 5) + p(x = 6) = .4557 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 124) According to data from the state blood program, 40 percent of all individuals have group A blood. If six individuals give blood, find the mean number of individuals having group A blood. A) 1.2 B) 1.55 C) 1.44 D) 2.4 Answer: D Explanation: μx = np = (6)(.4) = 2.4 Difficulty: 1 Easy Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 344 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 125) According to data from the state blood program, 40 percent of all individuals have group A blood. Suppose that of six randomly selected individuals, three have group A blood. Would you believe the data from the state blood program? A) Yes, probability is > .05. B) Yes, probability is < .05. C) No Answer: A Explanation: Yes, the probability is greater than 0.05, and therefore we do not reject the null hypothesis. Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 126) A lawyer believes that the probability is .3 that she can win a discrimination suit. If she wins the case, she will make $400,000; but if she loses, she gets nothing. Assume that she has to spend $75,000 preparing the case. What is her expected gain? A) $325,000 B) $45,000 C) $150,000 D) $22,500 Answer: B Explanation: μx = .7(−75,000) + .3(325,000) = −52,500 + 97,500 = 45,000 Difficulty: 3 Hard Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 345 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 127) The internal auditor for your company believes that 10 percent of your invoices contain errors. To check this theory, 20 invoices are randomly selected, and 5 are found to have errors. What is the probability that of the 20 invoices selected, 5 or more would contain errors if the theory is valid? A) .0433 B) .0319 C) .9567 D) .8660 Answer: A Explanation: P(x ≥ 5) = .0319 + .0089 + .0020 + .0004 + .0001 = .0433 Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 128) An important part of the customer service responsibilities of a cable company is the speed with which service troubles can be repaired. Historically, the data show that the likelihood is .75 that troubles in a residential service can be repaired on the same day. For the first five troubles reported on a given day, what is the probability that all five will be repaired on the same day? A) .0010 B) .6328 C) .7627 D) .2373 Answer: D Explanation: P(x = 5) = .2373 Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 346 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 129) An important part of the customer service responsibilities of a cable company is the speed with which service troubles can be repaired. Historically, the data show that the likelihood is .75 that troubles in a residential service can be repaired on the same day. For the first five troubles reported on a given day, what is the probability that fewer than two troubles will be repaired on the same day? A) .6328 B) .0879 C) .0156 D) .1035 Answer: C Explanation: P(x < 2) = P(x = 0) + P(x = 1) = .0156 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 130) An important part of the customer service responsibilities of a cable company is the speed with which service troubles can be repaired. Historically, the data show that the likelihood is .75 that troubles in a residential service can be repaired on the same day. For the first five troubles reported on a given day, what is the probability that at least three troubles will be repaired on the same day? A) .1035 B) .3672 C) .6328 D) .8965 Answer: D Explanation: P(x ≥ 3) = 1 − (P ≤ 2) = .8965 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 347 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 131) An important part of the customer service responsibilities of a cable company is the speed with which service troubles can be repaired. Historically, the data show that the likelihood is .75 that troubles in a residential service can be repaired on the same day. For the first five troubles reported on a given day, find the mean number of troubles repaired on the same day. A) 3.75 B) .94 C) 1.94 D) 2.50 Answer: A Explanation: μx = np = (5)(.75) = 3.75 Difficulty: 1 Easy Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 132) The Post Office has established a record in a major midwestern city for delivering 90 percent of its local mail the next working day. If you mail eight local letters, what is the probability that all of them will be delivered the next day? A) 1.0 B) .4305 C) .8131 D) .5695 Answer: B Explanation: P(x = 8) = .4305 Difficulty: 1 Easy Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 348 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 133) The Post Office has established a record in a major midwestern city for delivering 90 percent of its local mail the next working day. If you mail eight local letters, what is the average number you expect to be delivered the next day? A) 3.6 B) 4.0 C) 7.2 D) 2.7 Answer: C Explanation: μx = np = (8)(.9) = 7.2 Difficulty: 1 Easy Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 134) The Post Office has established a record in a major midwestern city for delivering 90 percent of its local mail the next working day. Calculate the standard deviation of the number delivered when 8 local letters are mailed. A) .85 B) .72 C) 2.68 D) 2.83 Answer: A Explanation: σ = = = = .85 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 349 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 135) The Post Office has established a record in a major midwestern city for delivering 90 percent of its local mail the next working day. When there are 8 local letters mailed, what is the probability that the number delivered will be within 2 standard deviations of the mean? A) .9950 B) .9619 C) .8131 D) .9996 Answer: B Explanation: P[σ = 7.2 ± 2(.85)] = P(σ = 7.2 ± 1.7) = P(5.5 ≤ x ≤8) = P(6 ≤ x ≤8) = .4305 + .3826 + .1488 = .9619 Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 136) A car wash loses $30 on rainy days and makes $120 on days when it does not rain. If the probability of rain is .15, calculate expected profit for the car wash. A) $90 B) $76.50 C) $106.50 D) $97.50 Answer: D Explanation: μx = (−30)(.15) + (120)(.85) = −4.50 + 102 = 97.50 Difficulty: 2 Medium Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 350 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 137) An insurance company will insure a $75,000 particular make and model of car for its full value against theft at a premium of $1,500 per year. Suppose that the probability that this particular automobile make and model will be stolen is .0075. Calculate the expected net profit for the insurance company. A) $937.50 B) $551.25 C) $1488.75 D) $562.50 Answer: A Explanation: μx = (−73,500)(.0075) + (1500)(.9925) = −551.25 + 1488.75 = 937.50 Difficulty: 3 Hard Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 138) An insurance company will insure a $75,000 particular automobile make and model for its full value against theft at a premium of $1500 per year. Suppose that the probability that this particular make and model will be stolen is .0075. Find the premium that the insurance company should charge if it wants its expected net profit to be $2000. A) $1437.50 B) $2551.25 C) $2562.50 D) $2062.50 Answer: C Explanation: 2000 = (x − 75,000)(.0075) + x(.9925) = .0075x − 562.5 + .9925x = 2562.5 Difficulty: 3 Hard Topic: Discrete Probability Distributions Learning Objective: 06-02 Find a discrete probability distribution and compute its mean and standard deviation. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 351 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 139) A large disaster cleaning company estimates that 30 percent of the jobs it bids on are finished within the bid time. Looking at a random sample of 8 jobs that it has contracted, calculate the probability that exactly 4 of the jobs were not completed within the bid time. A) .0081 B) .8059 C) .0580 D) .1361 Answer: D Explanation: P(x = 4) = .1361 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 140) A large disaster cleaning company estimates that 30 percent of the jobs it bids on are finished within the bid time. Looking at a random sample of 8 jobs that it has contracted, calculate the mean number of jobs completed within the bid time. A) 4.0 B) 2.4 C) 2.0 D) 5.6 Answer: B Explanation: μx = np = 8(.3) = 2.4 Difficulty: 2 Medium Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 352 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 141) A large disaster cleaning company estimates that 30 percent of the jobs it bids on are finished within the bid time. Looking at a random sample of 8 jobs that it has contracted, find the probability that x (number of jobs finished on time) is within one standard deviation of the mean. A) .6867 B) .2541 C) .5506 D) .8844 Answer: B Explanation: μx = np = 8(0.3) = 2.4 σ= = = 1.3 2.4 ± 1.3 = (1.1, 3.7), which convert to (2, 3) for discrete probability P(2 < x < 3) = 0.2541 Difficulty: 3 Hard Topic: The Binomial Distribution Learning Objective: 06-03 Use the binomial distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 142) Suppose that x has a hypergeometric distribution with N = 10, r = 5, and n = 3. Calculate the mean of the distribution. A) .500 B) .333 C) 1.500 D) 3.000 Answer: C Explanation: n(r/N) = 3(5/10) = 1.5 Difficulty: 3 Hard Topic: The Hypergeometric Distribution Learning Objective: 06-05 Use the hypergeometric distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 353 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 143) Suppose that x has a hypergeometric distribution with N = 10, r = 5, and n = 3. Calculate the standard deviation of the distribution. A) .583 B) .764 C) 1.500 D) .778 Answer: B Explanation: σ2 = n(r/N)(1 − r/N)[(N − n)/(N − 1)] = 3(5/10)(.5)(7/9) = .583 σ= = .764 Difficulty: 3 Hard Topic: The Hypergeometric Distribution Learning Objective: 06-05 Use the hypergeometric distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 144) If in a hypergeometric distribution r = 300, N = 600, and n = 30, estimate the binomial probability of success. A) .500 B) .333 C) .083 D) .250 Answer: A Explanation: P = r/N = 300/600 = .500 Difficulty: 3 Hard Topic: The Hypergeometric Distribution Learning Objective: 06-05 Use the hypergeometric distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 354 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 145) Suppose you randomly select 3 DVDs from a production run of 10. Of the 10 DVDs, 9 are expected to last a minimum of 3 years. What is the probability that all 3 of your DVDs will last at least three years? Answer: .7 P(x = 3) = (9C3 × 1C0)/10C3 = 84/120 = .7 Difficulty: 3 Hard Topic: The Hypergeometric Distribution Learning Objective: 06-05 Use the hypergeometric distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 146) Suppose you randomly select 3 DVDs from a production run of 10. Of the 10 DVDs, 9 are expected to last a minimum of 3 years. What is the mean of the random variable x? Answer: 2.7 Mean = n(r/N) = 3(9/10) = 2.7 Difficulty: 2 Medium Topic: The Hypergeometric Distribution Learning Objective: 06-05 Use the hypergeometric distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 147) Suppose you randomly select 3 DVDs from a production run of 10. Of the 10 DVDs, 9 are expected to last a minimum of 3 years. What is the standard deviation of the random variable x? Answer: .46 N = 10, n = 3, r = 9 S2 = n × (r/N) × [1 − (r/N)] × [(N − n)/(N − 1)] = (2.7 × .1 × .78) = .21 Therefore, standard deviation = s = = .46 Difficulty: 2 Medium Topic: The Hypergeometric Distribution Learning Objective: 06-05 Use the hypergeometric distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 355 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 148) Suppose you randomly select 3 DVDs from a production run of 10. Of the 10 DVDs, 9 are expected to last a minimum of 3 years. What values of x are within two standard deviations of the mean? Answer: 2 and 3 x = [2.7 ± 2(.46)] = (2.7 ± .92) = (1.78, 3.62) Difficulty: 3 Hard Topic: The Hypergeometric Distribution Learning Objective: 06-05 Use the hypergeometric distribution to compute probabilities. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 149) The yearly proportional return for stock G = x, the yearly proportional return for stock H = y, μx = .16, μy = .07, σx = .11, σy = .11, and σxy2 = .0321. Find the mean and standard deviation of the portfolio return: P = .45x + .55y. Answer: mean = .111; standard deviation = .148 μp = μ(.45x+.55y) = .45(.16) + .55(.07) = .111 σp = √[(.45)2(.111)2 + (.55)2(.111)2 + 2(.45)(.55)(.0321)] = = .148 Difficulty: 3 Hard Topic: Joint Distributions and the Covariance Learning Objective: 06-06 Compute and understand the covariance between two random variables. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 356 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 150) The yearly proportional return for stock G = x, the yearly proportional return for stock H = y, μx = .16, μy = .07, σx = .11, σy = .11, and σxy2 = .0321. Find the mean and standard deviation of the portfolio return: P = .5x + .5y. Answer: mean = .115, standard deviation = .149 μp = μ(.5x+.5y) = .5(.16) + .5(.07) = .115 σp = √[(.5)2(.11)2 + (.5)2(.11)2 + 2(.5)(.5)(.0321)] = = .149 Difficulty: 3 Hard Topic: Joint Distributions and the Covariance Learning Objective: 06-06 Compute and understand the covariance between two random variables. Bloom's: Apply AACSB: Analytical Thinking Accessibility: Keyboard Navigation 357 Copyright 2019 © McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.