Please assist me with figuring this problem out.
The income for the US has a normal distribution with a population mean of $50,000 and a population standard deviation of $4,000.
a. A random sample of 1600 people was taken. What is the probability that the mean income for that sample will be greater than $50,200?
b. A random sample of 400 people was taken. What is the probability that the mean income for that sample will be greater than $49,700?
c. A random sample of 100 people was taken. What is the probability that the mean income for that sample will be less than $49,000?