X/12=8/y solve for x and y

Abcd is a parallelogram find the valuse of x

How do you find principle and simple interest

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?