Question

Suppose that the height of male students at a large university is normally distributed with a mean of 69 inches and a standard deviation of 3.0 inches. If 16 samples consisting of 25 students each are obtained, what is the probability that the mean of these 16 samples is between 68 and 70 inches?

Answer 1

Z = (mean1 - mean2)/standard error of the mean (SEm)

SEm = SD/√n(in each sample)

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to these Z scores.

Answer 2

0.818