Chapter 7.5, Problem 23E

Finding Probabilities for Electronic Associates, Inc., Managers. In the EAI sampling problem (see Figure 7.5), we showed that for n = 30, there was .5034 probability of obtaining a sample mean within ±$500 of the population mean.

1. a. What is the probability that $\bar{x}$ is within $500 of the population mean if a sample of size 60 is used?
2. b. Answer part (a) for a sample of size 120.