(a) A committee on community relations in a college town plans to survey local businesses about the importance of students as customers. From telephone book listings, the committee chooses 278 businesses at random. Of these, 85 return the questionnaire mailed by the committee. The population for this study is
A. all businesses in the college town.
B. the 85 businesses that returned the questionnaire.
C. the 278 businesses chosen.
D. None of the above.
(b) An opinion poll contacts 1097 adults and asks them, " Which political party do you think has better ideas for leading the country in the 21st century?" In all, 663 of the 1097 say, " The Democrats." The sample in this setting is
A. all 235 million adults in the United States.
B. the 1097 people interviewed.
C. the 663 people who chose the Democrats.
D. None of the above.
(c) A sample of households in a community is selected at random from the telephone directory. In this community, 7% of households have no telephone, 13% have only cell phones, and another 24% have unlisted telephone numbers. The sample will certainly suffer from
A. undercoverage.
B. false responses.
C. nonresponse.
D. None of the above.