Statistics

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Circle the BEST answer.

1. An example of a quantitative variable is the horsepower of a car.

True False

2. An example of a qualitative variable is the make of a car.

True False

3. In an observational study, the variable of interest is called a response variable.

True False

4. In an experimental study, the aim is to manipulate or set the value of the response variable.

True False

5. Which of the following is NOT a qualitative variable?

A. The make of a TV

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

6. Which of the following is not 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. Answers A,B, and C

7. 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).

8. 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?

9. Using the following data table of the average hours per week spent on internet activities by 15-18 year olds for the years 1999-2008, construct the runs plot and interpret.

10. 822 customers were randomly selected from those who had recently bought a book over the internet. The chart below shows the breakdown of the classification of the book type:

What percentage of the books purchased were either sci-fi/fantasy or biographies? ______________

Show your work to receive ANY credit

11. Recently an advertising company called 200 people and asked to identify the company that was in an ad running nationwide. The following results were obtained:

What percentage of those surveyed were male OR could recall the company? _____________

Show your work to receive ANY credit

12. 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, 12, 22, 19, 16, 10, 28, 24, 6, 21, 20, 25, 5, 17, 8

Complete this frequency table for these data

Frequency Relative Freq. Percent Cumulative Freq. Percent

4<10

10<15

15<19

19<24

24<29

13/14/15/16/17. 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 12 patrons and had them get in line between 2 and 3 p.m. Each was given a stop watch to record the time they spent in line. The times recorded were as follows (in minutes):

118, 108, 116, 99, 120, 138, 118, 129, 121, 45, 130, 118

For 13-17, ……..Show your work +/or explain briefly how you did the calculation

13. What is the mean?___________

14. What is the median?_________

15. What is the mode?___________

16.What is the variance?____________

17. What is the standard deviation? __________

18. A normal population has 99.73 percent of the population measurements within _____ standard deviation(s) of the mean.

A. One

B. Two

C. Three

D. Four

19. 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

20. Researchers generally would prefer their data to:

A. Have a large standard deviation

B. Have a small standard deviation

C. Have a small mean

D. Have a large mean