Can someone help with statistics?

In the library on a university campus, there is a

sign in the elevator that indicates a limit of 16 persons. In

addition, there is a weight limit of 2500 pounds. Assume

that the average weight of students, faculty, and staff on

campus is 150 pounds, that the standard deviation is 27

pounds, and that the distribution of weights of individuals

on campus is approximately normal. If a random sample

of 16 persons from the campus is to be taken:

a. What is the expected value of the distribution of the

sample mean weight?

b. What is the standard deviation of the sampling distribution

of the sample mean weight?

c. What average weights for a sample of 16 people will

result in the total weight exceeding the weight limit

of 2500 pounds? x-bar> 156.25

d. What is the chance that a random sample of 16

people will exceed the weight limit?