The probability using the normal distribution.

Environmental Protection Agency (EPA) fuel economy estimates for automobile models tested recently predicted a mean of 24.80 mpg and a standard deviation of 6.2mpg for highway driving. Assume that a normal model can be applied.

(a) Draw the model for auto fuel economy. Clearly label it, showing what the 68-95-99.7 Rule predicts about miles per gallon.

(b) In what interval would you expect the central 68 percent of autos to be found?

(c) About what percent of autos should get more than 31 mpg?

(d) About what percent of cars should get between 31 and 37 mpg?

(e) Illustrate the gas mileage of the worst 2.5% of all cars.