100 PTS help all information in pictures below

How do you use the elimination method for this question? explain, because i really want to 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?

Item 1 solve for s. s+24=90 −114 −66 66 114