PrepTest 139, Section 4, Question 10

What we’re looking for

Working the answers

• A

  The pain ratings are different, and the conclusion is that the subjects experience pain differently. There is no equal result despite a disadvantage, followed by an inferred strength that explains the tie. This moves from different reports to different experiences.

• B
  Correct

  The hamsters gained the same amount of weight, just as the cars produced the same mileage. Our hamster ate more, which would tend to produce more weight gain, just as less efficient driving would tend to reduce X's mileage.

  To explain the equal result despite that difference, the argument says our hamster burned more calories. That extra calorie burning plays the role of X's greater fuel efficiency: a compensating advantage inferred from keeping the outcome equal under unequal conditions.

• C

  Roland moves faster coasting downhill than pedaling on level ground, then predicts an even faster trip by combining the hill with pedaling. This starts with different results and proposes combining helpful conditions. It doesn't infer a hidden advantage in one of two things from an equal result despite a disadvantage.

• D

  This does mention cases where the estimates are equal, so don't stop at “lower estimates on average.” But those equal estimates aren't achieved despite a condition that should have made one result worse. The argument uses one person's usual tendency to give lower estimates to claim that their matching estimates must be too high.

  We haven't been told the furniture's actual value. Two equal estimates could both be accurate. That unsupported judgment about overestimation differs from the cars' argument about a compensating advantage.

• E

  Jean sees well with glasses, and the author concludes that she would see less well without them. This compares one person's performance with and without an aid. It doesn't give two equal observed results under unequal conditions and infer a difference between the subjects.