A researcher claims that the mean resting pulse rate of all college basketball players in the United States is less than the mean resting pulse rate of all professional basketball players in the United States. The resting pulse rates of a random sample of 115 college basketball players were measured as were the resting pulse rates of a random sample of 80 professional basketball players. The mean resting pulse rates of the two groups were compared.
This study is a(n)
A) voluntary response.
B) observational study.
C) randomized comparative experiment.
D) experiment, but without randomization.

Question

Quizplus · Accepted Answer

This study is an observational study because it involves measuring or observing subjects without attempting to influence or modify the outcome. In this case, the researcher is simply recording the resting pulse rates of two different groups without trying to change those rates or the conditions under which they are measured.

A Researcher Claims That the Mean Resting Pulse Rate of All