Statistics
posted by Dorothy on .
The populaion mean annual salary of service desk managers is $48,000 with a standard deviation of $1,800. A sample of 36 service desk managers is randomly selected. What is the probability the mean annual salary of the sample is less then $47,550?

Z = (scoremean)/SEm
Score = sample mean
SEm = SD/√n
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.