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If a fair 6 sided cube is rolled 60 times, theoretically how many times should you expect to roll a 4 or a 5?

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?

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)