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Which statement about perfect cubes is true

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?

Varies inversely with x. if y=8.5 when x=-1 find x when y=-1