Question

A baseball analyst wants to determine the average speed of a fastball thrown in the major leagues this season. He chooses a week at random. During that week, he will measure the speeds of a sample number of pitches. Which sample below is included in the population that he is interested in and comes closest to being random? All pitches All fastballs All pitches by pitchers whose specialty is throwing fastballs All fastballs thrown by pitchers whose specialty is throwing fastballs

Answer 1

If the analyst wants an average of all fastballs, it is not useful to measure other pitches, nor is it useful to limit it to a subset of the pitchers.

So, the sample should draw from all fastballs.

Answer 2

All fast balls

Explanation:

Given that a baseball analyst wants to determine the average speed of a fastball thrown in the major leagues this season.

Hence he chooses a week at random.

Measuring the speeds of a sample number of pitches will not represent the average speed of fast ball.

Hence only fastballs thrown is relevant here.

If all fastballs thrown by pitchers whose specialty is throwing fastballs will not represent the fast balls as this sample is biased with specialists hence speed may be shown more than average

Hence answer is all fast balls.