What is the equation of the following graph?

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?

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much

Typically a point in a three dimensional cartesian coordinate system is represented by which of the following answers in the picture !