Question

The marketing department of a sports supply store wants to estimate the percentage of adults in the town who belong to a gym. Which statement describes a method that will help the marketing department accurately estimate this percentage?

A: Select the store’s first 20 customers every day for one week, and ask each person whether he or she belongs to a gym. Calculate the percentage of the total who say “yes.”


B:Take a random sample of adults in the town, and ask each person whether he or she belongs to a gym. Calculate the percentage of the total who say “yes.”


C:Take a random sample of the store’s adult customers, and ask what percentage of their friends belong to a gym. Calculate the mean of the responses.


D:Take a random sample of adults at the local park, and ask each person whether he or she belongs to a gym. Calculate the percentage of the total who say “yes.”

Answer 1

The correct answer would be Choice B.

If the owner wanted to get the best sample, he/she should try to make the sample as random as possible. Choice B is completely random. For the rest of the choices, the owner might get a biased sample because he/she is not asking a complete random sample of the population.