Statistics for Managers Using Microsoft Excel
Instruction and Data Collection
1) The process of using sample statistics to draw conclusions about true population parameters is
called
A) statistical inference.
B) the scientific method.
C) sampling.
D) descriptive statistics.
Answer: A
Keywords: inferential statistics
2) Those methods involving the collection, presentation, and characterization of a set of data in
order to properly describe the various features of that set of data are called
A) statistical inference.
B) the scientific method.
C) sampling.
D) descriptive statistics.
Answer: D
3) The collection and summarization of the socioeconomic and physical characteristics of the
employees of a particular firm is an example of
A) inferential statistics.
B) descriptive statistics.
C) a parameter.
D) a statistic.
Answer: B
4) The estimation of the population average family expenditure on food based on the sample
average expenditure of 1,000 families is an example of
A) inferential statistics.
B) descriptive statistics.
C) a parameter.
D) a statistic.
Answer: A
Keywords: inferential statistics
5) The universe or "totality of items or things" under consideration is called
A) a sample.
B) a population.
C) a parameter.
D) a statistic.
Answer: B
Keywords: population
6) The portion of the universe that has been selected for analysis is called
A) a sample.
B) a frame.
C) a parameter.
D) a statistic.
Answer: A
Keywords: sample
7) A summary measure that is computed to describe a characteristic from only a sample of the
population is called
A) a parameter.
B) a census.
C) a statistic.
D) the scientific method.
Answer: C
Keywords: statistic
8) A summary measure that is computed to describe a characteristic of an entire population is
called
A) a parameter.
B) a census.
C) a statistic.
D) the scientific method.
Answer: A
Keywords: parameter
9) Which of the following is most likely a population as opposed to a sample?
A) respondents to a newspaper survey.
B) the first 5 students completing an assignment.
C) every third person to arrive at the bank.
D) registered voters in a county.
Answer: D
Keywords: population, sample
10) Which of the following is most likely a parameter as opposed to a statistic?
A) The average score of the first five students completing an assignment.
B) The proportion of females registered to vote in a county.
C) The average height of people randomly selected from a database.
D) The proportion of trucks stopped yesterday that were cited for bad brakes.
Answer: B
Keywords: parameter, statistic
11) Which of the following is not an element of descriptive statistical problems?
A) An inference made about the population based on the sample.
B) The population or sample of interest.
C) Tables, graphs, or numerical summary tools.
D) Identification of patterns in the data.
Answer: A
12) A study is under way in Yosemite National Forest to determine the adult height of American
pine trees. Specifically, the study is attempting to determine what factors aid a tree in reaching
heights greater than 60 feet tall. It is estimated that the forest contains 25,000 adult American
pines. The study involves collecting heights from 250 randomly selected adult American pine trees
and analyzing the results. Identify the population from which the study was sampled.
A) The 250 randomly selected adult American pine trees.
B) The 25,000 adult American pine trees in the forest.
C) All the adult American pine trees taller than 60 feet.
D) All American pine trees, of any age, in the forest.
Answer: B
Keywords: population, sample
13) A study is under way in Yosemite National Forest to determine the adult height of American
pine trees. Specifically, the study is attempting to determine what factors aid a tree in reaching
heights greater than 60 feet tall. It is estimated that the forest contains 25,000 adult American
pines. The study involves collecting heights from 250 randomly selected adult American pine trees
and analyzing the results. Identify the variable of interest in the study.
A) The age of an American pine tree in Yosemite National Forest.
B) The height of an American pine tree in Yosemite National Forest.
C) The number of American pine trees in Yosemite National Forest.
D) The species of trees in Yosemite National Forest.
Answer: B
Keywords: variable
14) A study is under way in Yosemite National Forest to determine the adult height of American
pine trees. Specifically, the study is attempting to determine what factors aid a tree in reaching
heights greater than 60 feet tall. It is estimated that the forest contains 25,000 adult American
pines. The study involves collecting heights from 250 randomly selected adult American pine trees
and analyzing the results. Identify the sample in the study.
A) The 250 randomly selected adult American pine trees.
B) The 25,000 adult American pine trees in the forest.
C) All the adult American pine trees taller than 60 feet.
D) All American pine trees, of any age, in the forest.
Answer: A
Keywords: population, sample
15) Most analysts focus on the cost of tuition as the way to measure the cost of a college education.
But incidentals, such as textbook costs, are rarely considered. A researcher at Drummand
University wishes to estimate the textbook costs of first-year students at Drummand. To do so, she
monitored the textbook cost of 250 first-year students and found that their average textbook cost
was $300 per semester. Identify the population of interest to the researcher.
A) All Drummand University students.
B) All college students.
C) All first-year Drummand University students.
D) The 250 students that were monitored.
Answer: C
Keywords: population, sample
16) Most analysts focus on the cost of tuition as the way to measure the cost of a college education.
But incidentals, such as textbook costs, are rarely considered. A researcher at Drummand
University wishes to estimate the textbook costs of first-year students at Drummand. To do so, she
monitored the textbook cost of 250 first-year students and found that their average textbook cost
was $300 per semester. Identify the variable of interest to the researcher.
A) The textbook cost of first-year Drummand University students.
B) The year in school of Drummand University students.
C) The age of Drummand University students.
D) The cost of incidental expenses of Drummand University students.
Answer: A
Keywords: variable
17) Most analysts focus on the cost of tuition as the way to measure the cost of a college education.
But incidentals, such as textbook costs, are rarely considered. A researcher at Drummand
University wishes to estimate the textbook costs of first-year students at Drummand. To do so, she
monitored the textbook cost of 250 first-year students and found that their average textbook cost
was $300 per semester. Identify the sample in the study.
A) All Drummand University students.
B) All college students.
C) All first-year Drummand University students.
D) The 250 students that were monitored.
Answer: D
Keywords: population, sample
18) Researchers suspect that the average number of units earned per semester by college students
is rising. A researcher at Calendula College wishes to estimate the number of units earned by
students during the spring semester at Calendula. To do so, he randomly selects 100 student
transcripts and records the number of units each student earned in the spring term. He found that
the average number of semester units completed was 12.96 units per student. Identify the
population of interest to the researcher.
A) All Calendula College students.
B) All college students.
C) All Calendula College students enrolled in the spring.
D) All college students enrolled in the spring.
Answer: C
Keywords: population, sample
19) The average number of units earned per semester by college students is suspected to be rising.
A researcher at Calendula College wishes to estimate the number of units earned by students
during the spring semester at Calendula. To do so, he randomly selects 100 student transcripts and
records the number of units each student earned in the spring term. Identify the variable of interest
to the researcher.
A) The number of students enrolled at Calendula College during the spring term.
B) The average indebtedness of Calendula College students enrolled in the spring.
C) The age of Calendula College students enrolled in the spring.
D) The number of units earned by Calendula College students during the spring term.
Answer: D
Keywords: data, sampling
20) The chancellor of a major university was concerned about alcohol abuse on her campus and
wanted to find out the proportion of students at her university who visited campus bars on the
weekend before the final exam week. Her assistant took a random sample of 250 students and
computed the portion of students in the sample who visited campus bars on the weekend before the
final exam. The portion of all students at her university who visited campus bars on the weekend
before the final exam week is an example of
A) a statistic.
B) a population.
C) a sample.
D) a parameter.
Answer: D
Keywords: parameter
21) The chancellor of a major university was concerned about alcohol abuse on her campus and
wanted to find out the proportion of students at her university who visited campus bars on the
weekend before the final exam week. Her assistant took a random sample of 250 students. The
portion of students in the sample who visited campus bars on the weekend before the final exam
week is an example of ________.
A) a population.
B) a sample.
C) a parameter.
D) a statistic.
Answer: D
Keywords: statistic
TABLE 1-1
The manager of the customer service division of a major consumer electronics company is
interested in determining whether the customers who have purchased a DVD player made by the
company over the past 12 months are satisfied with their products.
22) Referring to Table 1-1, the population of interest is
A) all the customers who have bought a DVD player made by the company over the past 12
months.
B) all the customers who have bought a DVD player made by the company and brought it in for
repair over the past 12 months.
C) all the customers who have used a DVD player over the past 12 months.
D) all the customers who have ever bought a DVD player made by the company.
Answer: A
Keywords: population
23) True or False: A population is the totality of items or things under consideration.
Answer: TRUE
Keywords: population
24) True or False: A sample is the portion of the universe that is selected for analysis.
Answer: TRUE
Keywords: sample
25) True or False: Problems may arise when statistically unsophisticated users who do not
understand the assumptions behind the statistical procedures or their limitations are misled by
results obtained from computer software.
Answer: TRUE
Keywords: statistical package
Topics: Section 1.2 & Section 1.4
26) True or False: Managers need an understanding of statistics to be able to present and describe
information accurately, draw conclusions about large populations based on small samples,
improve processes, and make reliable forecasts.
Answer: TRUE
Keywords: reasons for learning statistics
27) True or False: A statistic is usually used to provide an estimate for a usually unobserved
parameter.
Answer: TRUE
Keywords: statistic, parameter
28) True or False: A statistic is usually unobservable while a parameter is usually observable.
Answer: FALSE
Keywords: statistic, parameter, inferential statistic
29) True or False: A professor computed the sample average exam score of 20 students and used it
to estimate the average exam score of the 1,500 students taking the exam was an example of
inferential statistics.
Answer: TRUE
30) True or False: Using the number of registered voters who turned out to vote for the primary in
Iowa to predict the number of registered voters who will turn out to vote in Vermont's primary is
an example of descriptive statistics.
Answer: FALSE
31) True or False: Compiling the number of registered voters who turned out to vote for the
primary in Iowa is an example of descriptive statistics.
Answer: TRUE
32) The Human Resources Director of a large corporation wishes to develop an employee benefits
package and decides to select 500 employees from a list of all (N = 40,000) workers in order to
study their preferences for the various components of a potential package. All the employees in the
corporation constitute the ________.
Answer: population
Keywords: population
33) The Human Resources Director of a large corporation wishes to develop an employee benefits
package and decides to select 500 employees from a list of all (N = 40,000) workers in order to
study their preferences for the various components of a potential package. The 500 employees who
will participate in this study constitute the ________.
Answer: sample
Keywords: sample
34) The Human Resources Director of a large corporation wishes to develop an employee benefits
package and decides to select 500 employees from a list of all (N = 40,000) workers in order to
study their preferences for the various components of a potential package. The Director will use
the data from the sample to compute ________.
Answer: statistics
Keywords: statistic
35) The Human Resources Director of a large corporation wishes to develop an employee benefits
package and decides to select 500 employees from a list of all (N = 40,000) workers in order to
study their preferences for the various components of a potential package. Information obtained
from the sample will be used to draw conclusions about the true population ________.
Answer: parameters
Keywords: parameter
36) The Human Resources Director of a large corporation wishes to develop an employee benefits
package and decides to select 500 employees from a list of all (N = 40,000) workers in order to
study their preferences for the various components of a potential package. In this study, methods
involving the collection, presentation, and characterization of the data are called ________.
Answer: descriptive statistics/methods
37) The Human Resources Director of a large corporation wishes to develop an employee benefits
package and decides to select 500 employees from a list of all (N = 40,000) workers in order to
study their preferences for the various components of a potential package. In this study, methods
that result in decisions concerning population characteristics based only on the sample results are
called ________.
Answer: inferential statistics/methods
Keywords: inferential statistics
38) Mediterranean fruit flies were discovered in California a few years ago and badly damaged the
oranges grown in that state. Suppose the manager of a large farm wanted to study the impact of the
fruit flies on the orange crops on a daily basis over a 6-week period. On each day a random sample
of orange trees were selected from within a random sample of acres. The daily average number of
damaged oranges per tree and the proportion of trees having damaged oranges were calculated.
The two main measures calculated each day (i.e., average number of damaged oranges per tree and
proportion of trees having damaged oranges) are called ________.
Answer: statistics
Keywords: statistic
39) Mediterranean fruit flies were discovered in California a few years ago and badly damaged the
oranges grown in that state. Suppose the manager of a large farm wanted to study the impact of the
fruit flies on the orange crops on a daily basis over a 6-week period. On each day a random sample
of orange trees were selected from within a random sample of acres. The daily average number of
damaged oranges per tree and the proportion of trees having damaged oranges were calculated.
The two main measures calculated each day (i.e., average number of damaged oranges per tree and
proportion of trees having damaged oranges) may be used on a daily basis to estimate the
respective true population ________.
Answer: parameters
Keywords: parameters
40) Mediterranean fruit flies were discovered in California a few years ago and badly damaged the
oranges grown in that state. Suppose the manager of a large farm wanted to study the impact of the
fruit flies on the orange crops on a daily basis over a 6-week period. On each day a random sample
of orange trees were selected from within a random sample of acres. The daily average number of
damaged oranges per tree and the proportion of trees having damaged oranges were calculated. In
this study, drawing conclusions on any one day about the true population characteristics based on
information obtained from the sample is called ________.
Answer: inferential statistics/methods
Keywords: inferential statistics
41) Mediterranean fruit flies were discovered in California a few years ago and badly damaged the
oranges grown in that state. Suppose the manager of a large farm wanted to study the impact of the
fruit flies on the orange crops on a daily basis over a 6-week period. On each day a random sample
of orange trees were selected from within a random sample of acres. The daily average number of
damaged oranges per tree and the proportion of trees having damaged oranges were calculated. In
this study, the presentation and characterization of the two main measures calculated each day
(i.e., average number of damaged oranges per tree and proportion of trees having damaged
oranges) is called ________.
Answer: descriptive statistics/methods
42) The Quality Assurance Department of a large urban hospital is attempting to monitor and
evaluate patient satisfaction with hospital services. Prior to discharge, a random sample of patients
is asked to fill out a questionnaire to rate such services as medical care, nursing, therapy,
laboratory, food, and cleaning. The Quality Assurance Department prepares weekly reports that
are presented at the Board of Directors meetings and extraordinary/atypical ratings are easy to flag.
Values computed from the sample results each week are called ________.
Answer: statistics
Keywords: statistic
43) The Quality Assurance Department of a large urban hospital is attempting to monitor and
evaluate patient satisfaction with hospital services. Prior to discharge, a random sample of patients
is asked to fill out a questionnaire to rate such services as medical care, nursing, therapy,
laboratory, food, and cleaning. The Quality Assurance Department prepares weekly reports that
are presented at the Board of Directors meetings and extraordinary/atypical ratings are easy to flag.
True population characteristics estimated from the sample results each week are called ________.
Answer: parameters
Keywords: parameter
44) The Commissioner of Health in New York State wanted to study malpractice litigation in New
York. A sample of 31 thousand medical records was drawn from a population of 2.7 million
patients who were discharged during the year 2009. The proportion of malpractice claims filed
from the sample of 31 thousand patients is a ________.
Answer: statistic
Keywords: statistic
45) The Commissioner of Health in New York State wanted to study malpractice litigation in New
York. A sample of 31 thousand medical records was drawn from a population of 2.7 million
patients who were discharged during the year 2009. The true proportion of malpractice claims filed
from the population of 2.7 million patients is a ________.
Answer: parameter
Keywords: parameter
46) The Commissioner of Health in New York State wanted to study malpractice litigation in New
York. A sample of 31 thousand medical records was drawn from a population of 2.7 million
patients who were discharged during the year 2009. Using the information obtained from the
sample to predict population characteristics with respect to malpractice litigation is an example of
________.
Answer: inferential statistics
47) The Commissioner of Health in New York State wanted to study malpractice litigation in New
York. A sample of 31 thousand medical records was drawn from a population of 2.7 million
patients who were discharged during the year 2009. The collection, presentation, and
characterization of the data from patient medical records are examples of ________.
Answer: descriptive statistics/methods
Data and Statistics
Solutions:
1.
Statistics can be referred to as numerical facts. In a broader sense, statistics is the
field of study dealing with the collection, analysis, presentation and interpretation of
data.
2. a. The ten elements are the ten cars
b. 5 variables: Size, Cylinders, City MPG, Highway MPG, and Fuel
c. Categorical variables: Size and Fuel
Quantitative variables: Cylinders, City MPG, and Highway MPG
d.
Variable
Measurement
Scale
Size
Cylinders
City MPG
Highway
MPG
Fuel
Ordinal
Ratio
Ratio
Ratio
Nominal
3. a. Average mpg for city driving = 182/10 = 18.2 mpg
b. Average mpg for highway driving = 261/10 = 26.1 mpg
On average, the miles per gallon for highway driving is 26.1 – 18.2 = 7.9 mpg greater
compared to city driving.
c. 3 of 10 or 30% have four cylinder engines
d. 6 of 10 or 60% use regular fuel
4. a. The seven elements are the seven schools shown
b. 5 variables: State, Campus Setting, Endowment, Applicants Admitted, and NCAA
Division
c. Categorical variables: State, Campus Setting, and NCAA Division
Quantitative variables: Endowment and Applicants Admitted
5. a. Average endowment = 74.6/7 = $10.657 billion
b. Average percentage admitted = 111/7 = 15.86%
c. 3 of 7 or 42.9% have NCAA Division III varsity teams
d. 3 of 7 or 42.9% have a City: Midsize campus setting
6. a. Quantitative
b. Categorical
c. Categorical
d. Quantitative
e. Categorical
7. a. Although the data are recorded as numbers, the numbers are codes for the ratings of
Fair (1), Average (2), Good (3) and Excellent (4). Thus the variables are categorical
with each data value corresponding to a rating category for the variable.
b. The data may also be ranked in order of the quality. A higher number indicates a
higher rating on a scale from Fair (1) to Excellent (4). Since the data can be ranked or
ordered, the scale of measurement is ordinal.
8. a. 1015
b. Categorical
c. Percentages
d. .10(1015) = 101.5
101 or 102 respondents said the Federal Bank is doing a good job.
9. a. Categorical
b. 30 of 71; 42.3%
10. a. Quantitative; ratio scale of measurement
b. Categorical; nominal scale of measurement
c. Categorical; ordinal scale of measurement since the responses can be ordered from
earliest (high school) to latest (retirement)
d. Quantitative; ratio scale of measurement
e. Categorical; nominal scale of measurement
11. a. Quantitative; ratio
b. Categorical; ordinal
c. Categorical; ordinal (assuming employees can be ranked by classification)
d. Quantitative; ratio
e. Categorical; nominal
12. a. The population is all visitors coming to the state of Hawaii.
b. Since airline flights carry the vast majority of visitors to the state, the use of
questionnaires for passengers during incoming flights is a good way to reach this
population. The questionnaire actually appears on the back of a mandatory plants
and animals declaration form that passengers must complete during the incoming
flight. A large percentage of passengers complete the visitor information
questionnaire.
c. Questions 1 and 4 provide quantitative data indicating the number of visits and the
number of days in Hawaii. Questions 2 and 3 provide categorical data indicating the
categories of reason for the trip and where the visitor plans to stay.
13. a. Federal spending measured in trillions of dollars
b. Quantitative
c. Time series
d. Federal spending has increased over time
Vehicles (millions)
14. a.
Toyota
GM
Ford
DC
Year
b. According to the CSM data, Toyota surpasses General Motors as the biggest auto
manufacturer in the world in 2006. In 2006, Toyota manufactured approximately
(9.1 – 8.9) = .2 million or 200,000 more vehicles than General Motors. The gap is
expected to widen to 800,000 vehicles in 2007. General Motors is the only
manufacturer showing a decline in vehicle production over the four year period.
c. The following is a bar chart of cross-sectional data as it shows the number of vehicles
manufactured in 2007.
12
Vehicles (millions)
10
8
6
4
2
0
GM
Ford
DC
Manufacturer
15. a. Quantitative – number of new drugs approved
Toyota
b. Time series from 1996 to 2003
c. 18
d. 2002; 16 new drugs
e. Over the eight-year period, the number of new drugs approved by the FDA declined.
From approximately 50 new drugs approved in 1996, the most recent years are
showing only 16 to 18 new drugs approved.
16.
The answer to this exercise depends upon the time series of the average price per
gallon of conventional regular gasoline since April 2009. Contact the website
www.eia.doe.gov to obtain the more recent time series data. In the spring of 2009, the
average price per gallon was once again increasing. A continuation of the usual
summer peak in gasoline prices was anticipated.
17.
Internal data on salaries of other employees can be obtained from the personnel
department. External data might be obtained from the Department of Labor or
industry associations.
18. a.
155
 .36
430
or 36%
b. 44% of 430 = .44(430) = 189 business travelers
c. Categorical data with categories online travel site, travel agent, direct with
airline/hotel, other.
19. a. All subscribers of Business Week in North America at the time the survey was
conducted.
b. Quantitative
c. Categorical (yes or no)
d. Crossectional - all the data relate to the same time.
e. Using the sample results, we could infer or estimate 59% of the population of
subscribers have an annual income of $75,000 or more and 50% of the population of
subscribers have an American Express credit card.
20. a. 43% of managers were bullish or very bullish.
21% of managers expected health care to be the leading industry over the next 12
months.
b. We estimate the average 12-month return estimate for the population of investment
managers to be 11.2%.
c. We estimate the average over the population of investment managers to be 2.5 years.
21. a. The two populations are the population of women whose mothers took the drug DES
during pregnancy and the population of women whose mothers did not take the drug
DES during pregnancy.
b. It was a survey.
c. 63 / 3.980 = 15.8 women out of each 1000 developed tissue abnormalities.
d. The article reported “twice” as many abnormalities in the women whose mothers had
taken DES during pregnancy. Thus, a rough estimate would be 15.8/2 = 7.9
abnormalities per 1000 women whose mothers had not taken DES during pregnancy.
e. In many situations, disease occurrences are rare and affect only a small portion of the
population. Large samples are needed to collect data on a reasonable number of
cases where the disease exists.
22. a. The population consists of all customers of the chain’s stores in Charlotte, North
Carolina.
b. Some of the ways that could used to collect the data are as follows:
 Customers entering or leaving the store could be surveyed
 A survey could be mailed to customers who have a shopper’s club card for the
stores
 Customers could be given a printed survey when they check out
 Customers could be given a coupon that asks them to complete a brief on-line
survey; if they do, they will receive a 5% discount on their next shopping trip.
23. a. Nielsen is attempting to measure the popularity of each television program by
showing the percentage of households that are watching the program.
b. All households with televisions in the United States.
c. A census of the population is impossible. A sample provides timely information in
that the ratings and share data can be obtained weekly. In addition, the sample saves
data collection costs.
d. The cancellation or renewal of television programs, advertising cost rates for the
television programs and the scheduling of television programs are often based on the
Nielsen information.
24. a. This is a statistically correct descriptive statistic for the sample.
b. An incorrect generalization since the data was not collected for the entire population.
c. An acceptable statistical inference based on the use of the word “estimate.”
d. While this statement is true for the sample, it is not a justifiable conclusion for the
entire population.
e. This statement is not statistically supportable. While it is true for the particular
sample observed, it is entirely possible and even very likely that at least some
students will be outside the 65 to 90 range of grades.
25. a. There are five variables: Exchange, Ticker Symbol, Market Cap, Price/Earnings
Ratio and Gross Profit Margin.
b. Categorical variables: Exchange and Ticker Symbol
Quantitative variables: Market Cap, Price/Earnings Ratio, Gross Profit Margin
c. Exchange variable:
Exchange Frequency Percent
Frequency
AMEX
5
(5/25) 20%
NYSE
3
(3/25) 12%
OTC
17
(17/25) 68%
25
80
Percent Frequency
70
60
50
40
30
20
10
0
AMEX
NYSE
Exchange
d. Gross Profit Margin variable:
Gross Profit Margin Frequency
0.0 – 14.9
2
15.0 – 29.9
6
30.0 – 44.9
8
45.0 – 59.9
6
60.0 – 74.9
3
OTC
9
8
Frequency
7
6
5
4
3
2
1
0
0.0-14.9
15.0-29.9
30.0-44.9
45.0-59.9
Gross Profit Margin
e. Sum the Price/Earnings Ratio data for all 25 companies.
Sum = 505.4
Average Price/Earnings Ratio = Sum/25 = 505.4/25 = 20.2
60.0-74.9