Assume that a population is normally distributed with a mean of 100 and a standard deviation of 15.

Assume that a population is normally distributed with a mean of 100 and a standard deviation of 15. Would it be unusual for the mean of a sample of 3 to be 115 or more? Why or why not?

What if the size for each sample was increased to 20? would a sample mean of 115 or more be considered unusual? why or why not?