A. What Population Do You Think the Poll Has in Mind?

Name ______Period ______

Sections 7.4 Homework Special Topics

1. An opinion poll calls 1334 randomly chosen residential telephone numbers, then the interviewer asks to speak with an adult member of the household to ask, “How many movies have you watched in a movie theater in the past 12 months?” a. What population do you think the poll has in mind?

b. In all, 931 people respond. What is the rate (percent) of nonresponse?

c. Many responses to this question are likely to be inaccurate. Why?

2. Randomized Response: Suppose 30 students in a class participate in a survey in which they each flip a coin and do not tell the result. If the result was “heads,” the student is supposed to say “yes.” If the result was “tails,” the student is supposed to give an honest answer to the question “Have you ever used a fake ID?” Suppose the results in the class are 18 “yes” answers and 12 “no” answers.

a. If students follow the procedure correctly, is it true that all students who answered “no” have not used a fake ID?

b. If students follow the procedure correctly, is it true that all students who have not used a fake ID answered “no”?

c. On average, about half of the students who have not used a fake ID flipped “tails,” so what is your best estimate of the true number of students who have not used a fake ID?

d. Based on the answer to part (c), what is your estimate of the true number and proportion of students who have used a fake ID?

e. Do we have any way to know which of the 18 “yes” answers are truthful? 3. The wording of questions can strongly influence the results of a sample survey. You are writing an opinion poll question about a proposed amendment to the Constitution. You can ask if people are in favor of “changing the Constitution” or “adding to the Constitution” by approving the amendment. One of these choices of wording will likely produce a much higher percent in favor. Which one? Why?

4. During the 2000 presidential compaign, the candidates debated what to do with the government surplus. The Pew Research Center asked two questions of random samples of adults. Both questions stated that social security would be “fixed”. Here are the uses suggested for the remaining surplus:

Should the money be used for a tax cut, or should it be used to fund government programs?

Should the money be used for a tax cut, or should it be spent on programs for educations, the environment, health care, crime-fighting and military defense?

One of these questions drew 60% favoring a tax cut; the other, only 22%. Which wording pulls the respondents toward a tax cut? Why?

5. Comment on each of the following as a potential sample survey question. Is the question clear? Is it slanted toward a desired result? a) Which of the following best represents your opinions on gun control? 1. The government should confiscate our guns. 2. We have the right to keep and bear arms. b) A freeze in nuclear weapons should be favored because it would begin a much needed process to stop everyone in the world from building nuclear weapons now and reduce to possibility of nuclear war in the future. Do you agree or disagree? c) In view of escalating environmental degradation and incipient resource depletion, would you favor economic incentives for recycling of resource-intensive consumer goods? d) It is estimated that disposable diapers account for less than 2% of the trash in today’s landfills. In contrast, beverage containers, third-class mail and yard wastes are estimated to account for about 21% of the trash in landfills. Given this, in your opinion, would it be fair to ban disposable diapers?

e) Some cell phone users have developed brain cancer. Should all cell phones come with a warning label explaining the danger of using cell phones?

f) Do you agree that a national system of health insurance should be favored because it would provide health insurance for everyone and would reduce administrative costs?