What happens when solving this with a 0 on the outside of the “()”?

Find the balance at the end of 4 years if 1000 is deposited at the rate of

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?

Solutions for 2x+7 less than or equal to 3x-5