Mike and kim invest $18,000 in equipment to print yearbooks for schools. each yearbook costs $5 to print and sells for $30. how many yearbooks must they sell before their business breaks even?

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?