Question 1039651
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Of course, the presence of 8th-grade students' responses skew the survey.  If you wanted to know what percentage of 25 to 30-year-old women participate in Pilates, would you include data from a group of 40-year-old men?  Every participant in a survey must be a member of the group about which you want to draw conclusions. That's why survey instruments gather demographic data as well as data that is the subject of the study.


So, A is wrong.  B is wrong for the reason you stated.  C is right for the reasons I gave. And D is wrong because not getting a response from everyone in the population is the whole point of random sampling.  What if Cecilia wanted to study all seventh-grade students in the state she lives in?  There are situations where it is impossible, or at least prohibitively expensive to survey every member of a population under study.


John
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My calculator said it, I believe it, that settles it
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