How to do this ? cause i don't understand

Monthly water bills for a city have a mean of $108.43 and a standard deviation of $32.09. find the probability that a randomly selected bill will have an amount greater than $155, which the city believes might indicate that someone is wasting water. would a bill that size be considered unusual?

Ineed with number 6 , explain how to get 1978

You deposit $5000 each year into an account earning 3% interest compounded annually. how much will you have in the account in 30 years?