PrepTest 152, Section 1, Question 12
A study found that most of the strokes(27 more words not shown)
The conclusion of the argument(12 more words not shown)
- Apatients who have(7 more words not shown)
- Bit is very(19 more words not shown)
- Cdoctors vary greatly(8 more words not shown)
- Dthe symptoms of(12 more words not shown)
- Eother studies have(10 more words not shown)
Reading the argument
More diagnosed strokes on the left doesn't necessarily mean more strokes occur on the left.
Diagnosis depends on which events get noticed. A stroke that prompts no medical attention might be missed, for example. Even a very serious event needn't necessarily produce a recorded diagnosis in this study. Those are possibilities, not facts we're given about either side of the brain. The point is that the diagnosed cases may not tell the whole story.
What we’re looking for
The author wants to conclude that right-side strokes are missed more often. To support that, I'd look for evidence that the actual numbers on the two sides are roughly equal. Then the imbalance in diagnosed cases would show a difference in how many cases doctors are catching.
Working the answers
- A
Other health problems don't establish how often strokes occur on either side or which ones doctors miss. Even if those problems complicated diagnosis, we would still need a reason they affect the right-left comparison in the direction the author claims.
- BCorrect
Suppose 100 strokes occur on each side, but doctors diagnose 90 on the left and only 10 on the right. They've missed 10 percent of the left-side strokes and 90 percent of the right-side strokes. The actual numbers needn't be those numbers; the example shows why a similar underlying frequency makes the diagnosed imbalance evidence that right-side strokes are more likely to go undiagnosed.
- C
Some doctors being more accurate than others doesn't establish a difference between the two sides of the brain. The more accurate doctors might be equally good at detecting both kinds, and the less accurate doctors equally bad. C needs another connection before it supports the specific comparison.
- D
Different symptoms could matter, but different doesn't tell us which symptoms are harder to recognize. The right-side symptoms could be more obvious, less obvious, or equally detectable. D alone doesn't support the claim that right-side strokes are missed more often.
- E
This supports the general possibility of missed strokes, but not the right-left difference. The undiagnosed minor strokes could occur mostly on the left, mostly on the right, or equally on both sides. Without that information, E doesn't establish the author's particular claim.
More Strengthen questions
Learn the LSAT our way
Our platform drills Strengthen questions at your level and adjusts as you improve.