PSAT Math Multiple-Choice Question 516: Answer and Explanation

Question: 516

There are 210 members of a fitness center. A poll answered by a random sample of 30 members found that 7 of those members own exercise equipment at home. Approximately how many of the total members of the fitness center can be expected to own exercise equipment at home?

• A. 187
• B. 49
• C. 37
• D. 30

Correct Answer: B

Explanation:

B

The question asks about a population based on information about a study of a sample from that population. Since the members were randomly selected, the rate of exercise equipment ownership found in the study should match that of the larger population. To extrapolate the study results, set up a proportion. In this case, the proportion is based on the number of exercise equipment owners out of the total of each group: . Cross-multiply to get 30x = 1,470. Divide both sides by 30 to get x = 49. The correct answer is (B).