1. An opinion poll contacts 1021 adults and asks them, “Which political party do you think has better ideas for leading the country in the 21st century?” In all, 723 of the 1021 say “the Democrats.” The sample in this setting is

2. In a part-to-whole relationship, we would say the population is the _________.

3. A committee on community relations in a college town plans to survey local businesses about the importance of students as customers. From the 10,000 businesses listed in the telephone book, the committee chooses 150 businesses at random. Of these, 72 return the questionnaire mailed by the committee. The sample is

4. A call-in poll asks who people are planning to vote for in the next presidential election. People who believe major change is needed are likely to be represented in this poll ________ than they should be, if the goal is to get results that are representative of all voters.

5. On January 2, 2008, the American Idol website (www.americanidol.com) conducted an online poll that asked respondents which contestant they liked best among six former contestants. To become part of the sample, respondents simply clicked on a response. Of the 941,434 responses to this poll, 55% voted for Clay Aiken. We can conclude that

6. A sample consisting of people who chose to have their opinions be part of a poll is a __________ sample.

7. If we use the range of a sample to estimate the range of a population, our estimate would likely be

8. You are using the table of random digits to choose a simple random sample of 6 students from a class of 30 students. You label the students 01 to 30 in alphabetical order. Go to line 113 of Table 7.1 (page 298). Of the labels corresponding to the six students selected for your sample, the label that is largest is _________.

9. You must choose an SRS of 10 of the 420 retail outlets in New York that sell your company’s products. How would you label this population to use Table 7.1 (page 298)?

10. From an alphabetical list of the 7200 salaried employees of a corporation, you label the employees 0001 to 7200. Using line 111 of Table 7.1 (page 298), choose an SRS of 5 of the 7200 employees. Of the five employees selected for your sample, the label that is the largest is ________.

11. Which of these is more likely to occur when selecting a sequence of three digits from a very large table of random digits?

12. There are _________ possibilities for each digit drawn from a table of random digits.

13. A sample of households in a community is selected at random from the telephone directory. In this community, 4% of households have no telephone and another 35% have unlisted telephone numbers. The sample will certainly suffer from

14. For the survey in Skills Check 3, the nonresponse rate is _________.

15. Nonresponse is a type of

16. In research about the population of a county with 100,000 inhabitants, a sample of 3000 households was selected to be interviewed. For 1200 of the 3000 households that researchers attempted to contact, there was no one home willing to participate. For this survey, the nonresponse rate was ________.

17. A clinical trial compares an antidepression medicine with a placebo for relief of chronic headaches. There are 36 headache patients available to serve as subjects. To choose 18 patients to receive the medicine, you would

18. An experiment is designed to see if a treatment is the __________ of the response.

19. A comparative experiment

20. A study of cell phones and the associated risk of brain cancer looked at a group of 519 people who have brain cancer. The investigators matched each cancer patient with a person of the same sex, age, and race who did not have brain cancer, then asked about their use of cell phones. This kind of study is known as __________.

21. Studies that follow subjects forward in time are called

22. A treatment consisting of a “dummy pill” that looks like real medicine (but isn’t) is known as a _________.

23. A study of religious practices among college students interviewed a sample of 125 students; 105 of the students said that they prayed at least once in a while. What is the sample proportion who said they pray?

24. Suppose that 35% of all adults in a population would say “good” and 65% would say “bad” if they were asked how they view the state of the economy. An opinion poll asks this question of an SRS of 1000 adults from the population. In repeated samples, the sample proportion who say “good” would follow a normal distribution, with the mean having a value of __________________.

25. Referring to Skills Check 24, the standard deviation of the distribution of the sample proportion of adults who view the economy as “good” is about

26. Referring to Skills Check 24, the standard deviation of the distribution of the sample proportion of all adults who view the economy as “bad” is _________.

27. The sample survey in Skills Check 23 actually called 150 students, but 25 of the students refused to say whether they pray. This nonresponse could cause the survey result to be in error. The error due to nonresponse

28. To the nearer half of a percentage point, the margin of error for a 95% confidence interval is __________ when we use the result of Skills Check 23 to estimate what percentage of all college students pray.

29. A survey of folk music fans yields this 95% confidence interval estimate of the proportion of fans who love the music of David Wilcox: 0.74 to 0.86. The estimated mean percentage of fans who love Wilcox’s music must be about

30. To the nearer percentage point, the margin of error for the survey in Skills Check 29 is _________.