Chapter 18, Problem 2E

LSAT The LSAT (a test taken for law school admission) has a mean score of 151 with a standard deviation of 9 and a unimodal, symmetric distribution of scores. A test preparation organization teaches small classes of 9 students at a time. A larger organization teaches classes of 25 students at a time. Both organizations publish the mean scores of all their classes.

1. a) What would you expect the sampling distribution of mean class scores to be for each organization?
2. b) If either organization has a graduating class with a mean score of 160, they’ll take out a full-page ad in the local school paper to advertise. Which organization is more likely to have that success? Explain.
3. c) Both organizations advertise that if any class has an average score below 145, they’ll pay for everyone to retake the LSAT. Which organization is at greater risk to have to pay?