PrepTest 133

[lcid:3628] Prep Test 133 LSAT — Logical Reasoning — S1 Logical reasoning

Question prompt

A survey of address Remaining source text redacted.
Why the credited answer is right

Credited answer: D

The notes below walk through why it fits the stem and how to eliminate the rest.

Question Type

Strengthen Questions

Answer choices

  1. A
    Within the past decade Remaining source text redacted.
    Why choice A is not credited
    Incorrect. While many people may have moved in and then out, plenty of households just moved out since there were twice as many as who moved in. This answer doesn't affect that stat, so it doesn't affect the argument.
  2. B
    Over the past century Remaining source text redacted.
    Why choice B is not credited
    Incorrect. First, there's no indication what the last census said. Second, even if it did show a loss, that would suggest a gain on this census, not another loss. Third, even that relies on assuming that past trends carry into the future, which is a common error in reasoning, not a basis for a correct answer to a Strengthen question.
  3. C
    Many people moving into Remaining source text redacted.
    Why choice C is not credited
    Incorrect. This answer weakens the argument by calling the underlying data into question.
  4. D
    Most adults moving out Remaining source text redacted.
    Why choice D matches the stem
    Correct. Argument or Facts:
    Argument

    Valid or Flawed:
    Flawed

    Question Type:
    Strengthen

    Stimulus Summary:
    Data from post offices and DMVs shows that twice as many households moved out of Weston as moved in, so when the census is done, we'll see a decline in Weston's population.

    Answer Anticipation:
    Two flaws for the price of one!

    First, the stimulus notes that the information is from address changes filed with the post office and DMV. We don't know about you, but some of our driver's licenses are still from an old address. Since the underlying data is self-reported, there's a chance that it's off. For instance, someone moving out of a city into the suburbs might be more interested in getting their license updated since they'll be driving more. Anything that suggests this data isn't skewed will strengthen the argument.

    Second, there's a jump from the premises, where households are discussed, to the conclusion, where population is discussed. If the households moving out of the city were smaller than the ones moving in, then it's possible that the population didn't decline despite the 2:1 ration of those moving out. Any answer that establishes the inbound households were the same size or smaller than the outbound ones, therefore, will strengthen this argument.

    Answer Explanation:
    This answer addresses the assumption made when the stimulus jumped from discussing "households" in the premises and "population" in the conclusion. If the households that moved out were bigger than the households that moved in, and more households moved out than in, there's almost no question that Weston's population is in steep decline.

    Key Takeaway:
    When a Strengthen question features two flaws, there's a good chance that a trap answer is going to address one of these flaws, but in a way that weakens the argument. These answers that have the opposite effect on the argument are tempting since they do affect the logic, so be careful!
  5. E
    Most people moving out Remaining source text redacted.
    Why choice E is not credited
    Incorrect. The work status/reasons for moving are out of scope as to the numbers. If something here were tied to household size, then it'd be relevant, but there's no discussion of that here.

What this tests

Discussion

  • Question 1 reply

    Started by alva