Chapter 6, Problem 7P

The College Board reported the following mean scores for the three parts of the SAT:

Assume that the population standard deviation on each part of the test is σ = 100.

1. a. For a random sample of 30 test takers, what is the sampling distribution of $\bar{x}$ for scores on the Critical Reading part of the test?
2. b. For a random sample of 60 test takers, what is the sampling distribution of $\bar{x}$ for scores on the Mathematics part of the test?
3. c. For a random sample of 90 test takers, what is the sampling distribution of $\bar{x}$ for scores on the Writing part of the test?