Help please

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?

Credit card a offers an introductory apr of 3.4% for the first three months and standard apr of 15.7% thereafter,

State one method by which you can recognize a perfect square trinomial.