See Problem 3.

Determine whether the sampling method is random, systematic, or stratified. Tell whether the method will produce a good sample.

15. A pollster randomly selects 100 people from each town in a certain candidate's district to see if they support the candidate.
16. A factory tests the quality of every thirtieth shirt made.
17. A printing company randomly selects 10 of 450 books it printed to see if all the books were printed properly.

See Problem 4.

Determine whether each question is biased. Explain your answer.

18. Since global warming is a big problem, do you support government funding of studies on global warming?
19. Where would you most like to go on vacation?
20. Do you prefer shopping online or the excitement of going to stores with friends?

    See Problem 5.

21. You want to find out how much time people in your town spend doing volunteer work. You call 100 homes in the community during the day. Of those surveyed, 85% are over the age of 60. How might this create bias in your survey results?
22. You want to find out how many people in your neighborhood have pets in their homes. You ask every fourth person at the local dog park. How might this create bias in your survey results?

    B Apply

23. Reasoning You review the results of survey questions given to two random samples of students from your school. The results are shown in the table below. Why are the results not the same?

    Favorite Color

    Color	Red	Blue	Green	Yellow	Pink	Purple	Black
    Group A	8	6	4	2	5	4	1
    Group B	7	7	3	0	6	5	2

24. Think About a Plan You want to find out what types of music students would like to listen to at the next school dance. How would you conduct a survey to find the music preferences of your entire school?
    • What sampling method can you use to choose an unbiased sample?
    • How can you write survey questions that are not biased?
25. Travel A travel agent wants to determine whether a trip to France is a popular vacation for young adults. How could each factor described below create bias in the survey results?
    1. The agent interviews people at an international airport.
    2. The agent asks, “Would you prefer to vacation in France or in Italy?”
    3. Of the people interviewed, 86% took a French class in high school.

Table of Contents