The Township of Middleton Sets the Speed Limit on Its

Short Answer

The township of Middleton sets the speed limit on its roads by conducting a traffic study and determining the speed (to the nearest 5 miles per hour) at which 80% of the drivers travel at or below. A study was done on Brown's Dock Road that indicated driver's speeds follow a normal distribution with a mean of 36.25 miles per hour and a variance of 6.25.
a. What should the speed limit be?
b. What percent of the drivers travel below that speed?