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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?

How to do this , and can some one explain

Define the type of sequence below. 7, 14, 28, 56, 112, a. neither arithmetic nor geometric b. arithmetic c. both arithmetic and geometric d. geometric