In the interval [0,pie/2] if cos s=0, what does s= ?

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?

Two times a number plus three times another number equals 4. three times the first number plus four times the other number is 7. find the numbers

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