Posted by anne on .
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?

statistics 
PsyDAG,
Z = (sample mean  mean)/standard error (SE) of mean
SEm = SD/√(n1)
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.