PSAT Math Multiple-Choice Question 398: Answer and Explanation

Question: 398

A medical testing company conducted an experimental study to determine which of three antihistamines is most effective for alleviating allergy symptoms. If the only allergies treated in the course of the study were pollen allergies, which of the following is true?

• A. The antihistamine that is found to be the most effective will work for all allergies.
• B. The antihistamine that is found to be the most effective will work only for pollen allergies.
• C. The study will be able to produce results concerning the effects of the antihistamines only on pollen allergies.
• D. The study is clearly biased and, therefore, not relevant to determining which antihistamine is most effective.

Correct Answer: C

Explanation:

C

Difficulty: Medium

Getting to the Answer: The study only looked at pollen allergies, so the sample was limited. You can eliminate (A) because not all allergies were included in the sample—you can't say anything about them one way or the other. You can eliminate (B) by similar reasoning: the antihistamine found to be most effective for pollen allergies may or may not be the most effective one for other types of allergies as well; there is just no way to tell. You can eliminate (D) because the question doesn't tell you anything about the data collection methods, so you can't determine whether the study was biased. This means that (C) is correct—the study will be able to produce results concerning the effects of the antihistamines only on pollen allergies.