Sampling Disstributions and Confidence Intervals

On the Johannesburg Stock Exchange, the share Scamhoff has a standard deviation of monthly returns of 15% per month, and a mean return of 3.14% per month. Data on the return of Scamhoff was collected over 60 months. a) What is the probability that the sample mean return that will be obtained from the sample will exceed 5% per month?

b) The sample mean of the sample of 60 months was calculated and found to be 1.98% per month, assuming we were not told the value of the population mean, find a 99% confidence interval for it.