Practice and Problem-Solving Exercises

A Practice

See Problem 1.

Identify the sampling method. Then identify any bias in each method.

6. A supermarket wants to find the percent of shoppers who use coupons. A manager interviews every shopper entering the greeting card aisle.
7. A maintenance crew wants to estimate how many of 3000 air filters in an office building need replacing. The crew examines five filters chosen at random on each floor of the building.
8. The student government wants to find out how many students have after-school jobs. A pollster interviews students selected at random as they board buses at the end of the school day.

See Problem 2.

Identify any bias in each survey question.

9. Do you feel that you spend too much time each week doing academic homework and household chores?
10. Do you prefer reading exciting historical novels or dull autobiographies?
11. Don't you agree that the wrestling team doesn't get enough coverage in the school newspaper?

See Problem 3.

12. 1. Energy What sampling method could you use to find the percent of adults in your community who support building more nuclear power plants?
    2. What is an example of a survey question that is likely to yield unbiased information?

B Apply

A university researcher is studying the effect of watching television on residents of the city. Describe a sampling method that can be used for each population.

13. all teenagers
14. all homeowners
15. all women over the age of 21
16. all children under the age of 13

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