X^2-3x+8 is x=4 will choose

This is about circle theorems. someone asap : (

Explain how to graph a scatterplot and its regression line using a regression calculator.

Monthly water bills for a city have a mean of $108.43 and a standard deviation of $36.98. find the probability that a randomly selected bill will have an amount greater than $173, which the city believes might indicate that someone is wasting water. would a bill that size be considered unusual?