Need help asp being timed

Which term best describes the association between variables a and b

What could explain what happened when the time was equal to 120 minutes

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?