PrepTest 146, Section 3, Question 1

What we’re looking for

Working the answers

• A
  Correct

  The population is all 5,000 recipients, and the subgroup is the 300 respondents. The argument uses the subgroup's opinions to estimate the population's opinions without addressing how people ended up in that subgroup. If supporters are more likely to return the survey, the responses will overstate support among all recipients.

  We don't have to prove that most recipients disagree. The criticism is that the method gives us a reason to doubt whether these respondents represent the larger group.

• B

  This asks whether the same person's answer would change over time: would someone agree on Monday but disagree on Wednesday? The argument doesn't compare responses from different occasions. Its problem is moving from one group of people to a larger group, even if everyone's opinions remain completely stable.

• C

  The respondents could all have reported their opinions honestly and the sample problem would remain. C instead claims that the survey occurred under conditions likely to produce inaccurate responses. If people were pressured to say they agreed, that could be a problem, but the passage describes no such pressure. We aren't given a reason to think most respondents misrepresented their views.

• D

  This goes in the opposite direction. It describes knowing what a majority of the larger population thinks and using that to infer the opinions of a smaller group. A candidate could win a town while losing a particular neighborhood, for example. Here, though, the evidence concerns the smaller group of respondents, and the conclusion concerns all recipients.

• E

  The argument doesn't need the letter to change anyone's mind. It could assume everyone already held the reported opinions before receiving it. The question is whether the responses reveal the views of the entire mailing list, not whether the letter persuaded people to adopt those views.