Statistics show on average adult person receives 425 pieces of mail each and every year with standard deviation of 50.
Determine the mean and the standard deviation of a sampling distribution if all possible samples of size 100 are selected?.
What is the probability a person chosen at random received less than 475 pieces of mail in a year?
What is the probability the mean of a random sample of 400 persons is more than 415 pieces of mail per year?