PrepTest 123

[lcid:3590] Prep Test 123 LSAT — Logical Reasoning — S3 Logical reasoning

Question prompt

Advertisement:  Fabric-Soft leaves clothes soft Remaining source text redacted.
Why the credited answer is right

Credited answer: E

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

Argument or Facts

Argument

Valid or Flawed

Flawed

Question Type

Errors in Reasoning Questions

Stimulus Summary

99% of people in a sample of over 100 preferred a Fabric-Soft towel to a towel washed without Fabric-Soft, so Fabric-Soft is the most effective fabric softener.

Answer Anticipation

Whenever a study is done, a sampling error should be considered. Here, while it might seem small, over 100 people will generally be a large enough sample to justify a conclusion unless we're given a specific reason to doubt the representativeness of that sample. There's nothing in the stimulus suggesting the people in the study aren't representative of people generally, but a correct answer could bring up a reason to believe that, so we should be thinking about that as we analyze them.
Separate from a potential sampling error, there's a huge term shift here. If you're not seeing a flaw, a good place to look is the conclusion to see if there are any concepts that are new, and are thus not supported by the premises. Here, the conclusion is that Fabric-Soft is the most effective fabric softener—in other words, it's more effective than any other softener. There are two new ideas there. First, effectiveness. The study is about consumer preference, which isn't the same as effectiveness. Second, the study compared a Fabric-Soft towel to a towel washed without fabric softener. To support the conclusion, the study would have to compare Fabric-Soft to all other fabric softeners.
To sum up, we have three potential answers:
(1) An answer pointing out a reason to believe the sample is unrepresentative, though this is less likely since no information in the stimulus suggests this.
(2) An answer highlighting the jump from consumer preference to effectiveness.
(3) An answer highlighting the jump from a comparison with a softener-less towel to a conclusion with a comparison to all other fabric softeners.

Answer choices

  1. A
    any of the consumers Remaining source text redacted.
    Why choice A is not credited
    Incorrect. If the conclusion compared Fabric-Soft to no fabric softener, then allergic consumers might be relevant. However, since the conclusion compares Fabric-Soft to all other softeners, those who are allergic would have a similar reaction to all of the softeners, and thus wouldn't be relevant to the comparison.
  2. B
    Fabric-Soft is more or Remaining source text redacted.
    Why choice B is not credited
    Incorrect. The argument is about effectiveness, not environmental friendliness. This answer is out of scope.
  3. C
    Fabric-Soft is much cheaper Remaining source text redacted.
    Why choice C is not credited
    Incorrect. The argument is about effectiveness, not affordability, so this answer choice is out of scope.
  4. D
    the consumers tested find Remaining source text redacted.
    Why choice D is not credited
    Incorrect. While the premises compare Fabric-Soft to no softener, the conclusion isn't about that comparison. The conclusion is about Fabric-Soft vs. all other softeners. Since that's the relevant comparison, overlooking whether people find the benefits of softeners generally to be worth the expense isn't an error in this argument.
  5. E
    the consumers tested had Remaining source text redacted.
    Why choice E matches the stem
    Correct. This answer choice highlights the jump between the comparison in the study and the comparison in the conclusion. If the consumers in the study never compared Fabric-Soft to other softeners, then the study doesn't support a conclusion about Fabric-Soft being more effective than those other softeners.

What this tests

Discussion

  • Number 7 2 replies

    Started by jordyndickey

View all discussions Start a discussion