BA 275
Winter 2007
Quiz 1
Answer Key
Quiz #1
Name
(please print)
Section
One of the conclusions of the Nationwide Personal Transportation Survey was that "In 1990,
women drove 76% more on average than they did in 1969. However, women still drove 7,000
miles less on average than men in a year."
Question 1. What is the numerical value of 76% an example of?
A.
B.
C.
D.
E.
A population parameter based on driving behavior in 1990
A population parameter based on comparing driving behavior in 1969 and 1990
A sample statistic based on driving behavior in 1990
A sample statistic based on comparing driving behavior in 1969 and 1990
None of the above
Answer
D. 76% was calculated based on a survey.
Question 2. What is the numerical value of 7,000 miles an example of?
A.
B.
C.
D.
E.
A population parameter based on comparing driving behavior in 1969 and 1990
A sample statistic based on driving behavior in 1990
A sample statistic based on comparing driving behavior in 1969 and 1990
A population parameter based on driving behavior in 1990
None of the above
Answer
B. 7,000 was calculated based on a survey.
Question 3. Researchers designed an experiment to determine whether zinc lozenges reduce the
severity of the common cold. All the people in the study (the subjects) were given a cold, by
spraying a mist laden with a rhinovirus into their noses. People were randomly assigned to the
treatment and control groups. Those in the treatment group used zinc lozenges while people in
the control group used a placebo. The participants stayed at a retreat for ten days as their colds
developed and passed. Their used Kleenexes were collected, counted, and weighed each day.
Identify the data types of the following variables (circle the correct answer.)
Variable
Type of Data
Control vs. treatment group
Quantitative
Qualitative
Length of cold in days
Quantitative
Qualitative
Whether the subject got a cold or not.
Quantitative
Qualitative
Number of Kleenexes used
Quantitative
Qualitative
Hsieh, P-H
1
BA 275
Winter 2007
Quiz 1
Answer Key
Zinc lozenges vs. placebo
Quantitative
Qualitative
Weight of used Kleenexes
Quantitative
Qualitative
Question 4. A college researcher surveys a random sample of 500 students. Among other
things, the survey asks whether students have observed any instance of racial discrimination on
campus. One hundred students return completed surveys, and 53 report having observed such
discrimination. The researcher then reports that racial discrimination is common on campus. This
report is:
A. Invalid because the sample is such a small percent of the student body
B. Invalid because it is a volunteer sample (only people feeling strongly about racial
discrimination would fill out the survey.)
C. Valid because the sample is random
D. Valid because the sampling frame is the entire student population
Question 5. A set of data whose histogram is bell shaped yields a sample mean and standard
deviation of 50 and 4, respectively. Approximately what proportion of observations
a. Are between 42 and 62? → 97.35%
b. Are less than 46? → 16%
c. Are less than 58? → 97.5%
d. Are greater than 54? → 16%
This question came from Week 2
assignment and, as a result, no
penalty was imposed.
Question 6. Given the data below, complete the following summary statistics table. (Data are in
ascending order): 10.0, 10.5, 12.2, 13.9, 13.9, 14.1, 14.7, 14.7, 15.1, 15.3, 15.9, 17.7, 18.5, 19.3,
22.1.
Variable X
Count
Average
Median
Variance
Standard deviation
Minimum
Maximum
Range
Lower quartile
Upper quartile
Interquartile range
Sum
Hsieh, P-H
15
15.193 = SUM / Count
14.7
10.3778
3.22146 = variance
10
22.1
12.1 = max – min
13.9
17.7 = IQR + Lower quartile
3.8
227.9
2