Quiz:

Multiple-Choice: Choose exactly ONE answer for each question.

1. A few of the variables for which data were collected in a certain study include age, gender, income, and number of hours spent shopping online per month. Which of the variables is qualitative?
A. Age.
B. Gender.
C. Income.
D. Number of hours spent shopping online.
E. None.
Consider the following to answer the next two questions:
The administration of a large university is interested in learning about the types of wellness programs that would interest its employees. To do this, they plan to survey a sample of their employees.

2. Suppose that there are five categories of employees (administration, faculty, professional staff, clerical and maintenance) and the university decides to randomly select ten individuals from each category. This sampling plan is called
A. Simple Random Sampling.
B. Stratified Sampling.
C. Cluster Sampling.
D. Systematic Sampling.
E. Convenience Sampling.

3. Suppose that the university randomly selects a school (e.g., the Business School) and surveys all of the individuals (administration, faculty, professional staff, clerical and maintenance) who work in that school. This sampling plan is called
A. Simple Random Sampling.
B. Stratified Sampling.
C. Cluster Sampling.
D. Systematic Sampling.
E. Convenience Sampling.

Consider the following to answer the next two questions:

The box-plots below show monthly sales revenue figures ($ thousands) for a discount office supply company with locations in three different regions of the U.S. (Northeast, Southeast and West).

4. Which of the following statements is true?
A. The southeast has the lowest sales revenues.
B. The southeast has the lowest median sales revenue.
C. The west has the lowest mean sales revenue.
D. The west has the lowest median sales revenue.
E. None of the above.

5. Which of the following statements is false?
A. The west has the most variable sales revenues.
B. The west has the largest IQR.
C. The southeast has the smallest IQR.
D. The northeast has the most variable sales revenues.
E. The southeast has the least variable sales revenues.

6. The collection of all subjects that are being studied is
A. The sample.
B. The population.
C. Statistical inference.
D. Descriptive statistics.
E. None of the above.

7. Temperature in Fahrenheit or Centigrade scale is an example of a variable that uses
A. the ratio scale
B. the interval scale
C. the ordinal scale
D. the nominal scale
E. none of the above

Consider the following to answer the next four questions.

Below is a histogram and the five number summary for salaries (in $) for a sample of U.S. marketing managers.

8. The shape of this distribution is
A. symmetric.
B. bimodal
C. right skewed.
D. left skewed.
E. normal

9. The most appropriate measure of central tendency for these data is the
A. Median.
B. Mean.
C. Mode.
D. Range.
E. Standard deviation.

10. The IQR for these data is
A. $83,060
B. $69,693
C. $77,020
D. $14,566
E. $22,057

11. Suppose the marketing manager who was earning $129,420 got a raise and is now earning $140,000. Which of the following statement is true?
A. The mean would increase.
B. The median would increase.
C. The range would increase.
D. Both A and C.
E. All of the above

12. A student earned grades of 78, 78, 91, and 91 on her four tests. She earned 78 on the final exam and 87 on her class project. Her combined homework grade was 87. The four tests count for 40% of the final grade, the final exam counts for 30%, the project counts for 10% and the homework counts for 20%. What is her weighted mean grade? Roundto one decimal place.
A. 84.2
B. 82.8
C. 83.3
D. 84.3
E. none of the above

13. Identify the five-number summary of the following data set: 11, 28, 21, 7, 43, 33, 32, 37.
A. 7, 16, 30, 35, 43
B. 7, 21, 30, 33, 43
C. 7, 11, 30, 37, 43
D. 7, 21, 28, 33, 43
E. none of the above

14. Find the Variance and Standard deviation for the following sample data:

A. Variance = 0.86, Standard deviation = 0.74
B. Variance = 0.74, Standard deviation = 0.86
C. Variance = 0.64, Standard deviation = 0.80
D. Variance = 0.80, Standard deviation = 0.64
E. none of the above

15. One of the most widely used measures of dispersion is
A. the mean
B. the range
C. the z-score
D. the IQR
E. none of the above

The test scores of a sample of 40 students are summarized in the frequency distribution below. Use this information to do the next two problems:

16. Find the mean.
A 8.0
B 74.5
C 75.5
D 75.3
E None of the above

17. Find the standard deviation.
A. 12.3
B. 12.5
C. 15.6
D. 12.0
E. None of the above

18. A measurement obtained by using all the data values for a specific population is called
A. A variable.
B. The mean.
C. The standard deviation.
D. A statistic.
E. A parameter.

Use the following information to do the next two problems:

A survey of 800 College seniors produced the following contingency table (cross-tabulation) regarding their undergraduate major and whether or not they planned to go to graduate school.

19. Of those students that are majoring in Business, what percent plans to go to graduate school?
A. 27.78%
B. 8.75%
C. 70%
D. 72.22%
E. none of the above

20. Among the students who plan to go to graduate school, what percent indicated "Other" majors?
A. 15.75%
B. 45%
C. 49.22%
D. 32%
E. none of the above

Standard deviation

21. Is the following a probability distribution? If yes, find its men and standard deviation.