Need help with these problems thanks

A sample of n = 4 scores is selected from a normal population with a mean of = 50 and a standard deviation of = 20. What is the probability of obtaining a sample mean less than M = 52?

If a sample of n = 4 scores is obtained from a normal population with = 70 and = 12, what is the z-score corresponding to a sample mean of M = 69?