Q24 - A recent poll of a large number of households

[Laura Damone]

Question Type:
ID the Flaw

Stimulus Breakdown:
Conclusion: people with degrees are more likely to live with a cat than a dog. Premise: 47% of cat households had someone with a degree vs. only 38% of dog households.

Answer Anticipation:
Whenever we see percentages on the LSAT, we want to think about the Percent vs. Amount flaw. This premise is strictly about percents, but the conclusion is about amounts. It implies that there are more degree holders living with cats than with dogs. Certainly the lower percentage could be explained in this way, but there are other possible explanations too. The most common alternative deals with the size of the groups from which the percentages are calculated. A small percentage of a big group can be a higher number than a large percentage of a small group. So, if the number of dog households is a lot bigger than the number of cat households, 38% of dog households might be a bigger number than 47% of cat households.

Correct answer:
B

Answer choice analysis:
(A) Tempting! It's easy to think that this argument has overlooked overlap. But in fact, it's fine if some degree holders are counted in both the dog household and cat household percentages. That wouldn't mess up the argument, so ignoring this possibility isn't the argument's flaw.

(B) Bingo! The argument takes for granted that there aren't way more dog households than cat households, because if there were, the difference in percent wouldn't reflect a similar difference in amount. This matches our prediction exactly.

(C) Folks without degrees are outside the scope of this argument.

(D) Who makes the decisions is also outside the scope of this argument.

(E) Causation vs. Correlation is not the flaw we're looking for.

Takeaway/Pattern:
At least one question on pretty much every LSAT will test your understanding of percentages and amounts. Specifically, it will test whether you understand the extent to which a difference in percentage does and does not reflect a difference in amount. Remember, a small percentage of a large number can be as big or bigger than a large percentage of a small number.

#officialexplanation

[RogerD345]

Hi. Most importantly, i am tremendously thankful for Manhattan prep's PT 85 Answers to help the students out
Where can we find the answer for the
last question of PT.85's Section 3, Q.25 - Keeler wanted the institute to receive bad publicity (math the Flaw Question)