Logical reasoning PrepTest 119 · Section 3 · Question 3

Incorrect. That specific amount isn't important to the argument—what matters is that it's higher than what most rats eat.

Incorrect. The conclusion limits itself to discussing a link between a high-salt diet and high blood pressure in rats, not the health implications of this link. This answer is out of scope.

Incorrect. This answer might allow us to know if high blood pressure is a problem in many rat colonies, but it doesn't tell us anything about that link existing in the first place.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Argument Evaluation

Stimulus Summary:
Study - Rats were fed a lot of salt. After a few months:
(1) 25% had normal blood pressure
(2) 70% had high blood pressure
(3) 5% had very high blood pressure
Conclusion - High-salt diets are linked to high blood pressure in rats

Answer Anticipation:
Argument Evaluation questions will generally present answers that ask a question addressing a flaw or assumption in the argument, so we should approach these questions as we do any flaw-based question.

Here, there's a study, so we should start by considering a sampling flaw, and a correlation/causation flaw.

For the sampling flaw, the study involved a colony of rats, which is likely a large enough sample. The conclusion is about rats, not humans or all animals, so the sample is of a representative species. We don't know, however, if this colony is representative of all rats in relevant ways—maybe it started with high blood pressure. Any answer that questions this starting point could help evaluate the argument.

For the correlation/causation flaw, the conclusion actually isn't causal—it states that high-salt diets "are linked to" high blood pressure, which is a correlative statement. Since the conclusion isn't causal, there's no correlation/causation flaw here!

Answer Explanation:
This answer asks about the starting point. If the rat colony had members that mainly had normal blood pressure, then the elevated levels after eating the high-salt diet does support the conclusion. If the rat colony started with very high blood pressure, on average, then the results don't support the conclusion. Since there are answers to this question that strengthen the argument and others that weaken it, this is our answer.

Key Takeaway:
One way to look at an Argument Evaluation question is as a Strengthen/Weaken question. The piece of information raised should have a different and opposite effect on the argument depending on the answer or specifics—some that strengthen, some that weaken.

Incorrect. First, without knowing the results, this question wouldn't really tell us much of relevance to the argument. Second, the conclusion limits the argument to being about rats, so other rodents are out of scope.