posted by anne .
A population is normally distributed with a mean of 40 and a standard deviation of 6. For samples of size 10, what is the probability that the sample mean will be more than 42?
Z = (sample mean - mean)/standard error (SE) of mean
SEm = SD/√(n-1)
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the Z score.