Find the least and greatest amounts of rain in the data least amount: greatest amount: 3/4 1/8 1/4 1/2

Adiverr from the university of florida women’s swimming and diving team is competing in the ncaa zone b championships

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?

Having a hard time understanding this question (see attachment).