PrepTest 137

Incorrect. The stimulus notes that the study was of "all" the residents of Groverhill, so it wasn't even a sample—it was the whole population.

Incorrect. If residents were visiting doctors outside of Groverhill, then there should be more people with headaches than the doctors would report, not fewer.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Errors in Reasoning

Stimulus Summary:
Study - All Groverhill residents
35 said they went to the doc for a bad headache
Doctors reported 105 severe headache consults
Explanation - Many residents forgot they went to the doc for headaches

Answer Anticipation:
This stimulus falls into a common pattern—the phenomenon/explanation argument. The stimulus notes that there were more consults for severe headaches than there were people who reported going to the doctor for that reason, and the argument concludes it's because many residents forgot about it. However, there are many other explanations for that discrepancy, one of which is suggested by another LSAT pattern.

Whenever the LSAT starts digging into specific numbers for group sizes, it tends to neglect the possibility of things being "doubled up." What that means here is that while there were 105 severe headache consults for only 35 patients, it's possible that those patients each went in for multiple consults—those 35, in other words, might count multiple times in that 105. The shift in what the numbers discuss—from patients to visits—highlights this alternative explanation for the discrepancy.

Answer Explanation:
This answer highlights the shift from discussing the number of patients to the number of visits, which is the flawed jump in the argument.

Key Takeaway:
When an argument concludes one explanation for a phenomenon, alternative explanations should be your first thought. And when the LSAT starts comparing numbers, always think about whether something might be double counted.

Incorrect. The argument never states that this rate of headache is unusually high. Even if it were, the argument wouldn't need to provide evidence for it if established as a premise.

Incorrect. If the residents were asked whether they suffered from a severe headache, then this answer might describe a flaw. However, they were asked whether they visited a physician for a severe headache, so the assumption suggested by this answer isn't present in the argument.