Help on math plz taking quiz

What properties allow transformation to be used as a problem solving tool

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?

Me asap! what is the slope of this line? enter your answer in the box.