Quiz 2

1.

Fuel economy estimates for automobiles built one year predicted a mean of 26.2 mpg and a standard deviation of 6.8mpg for highway driving. Assume that a Normal model can be applied. Use the 68 – 95 – 99.7 Rule to complete parts​ a) through​ e).

Draw the model for auto fuel economy

In what interval would you expect the central 68​% of autos to be​ found?

Using the​ 68-95-99.7 rule, the central 68​% of autos can be expected to be found in the interval from _____ to ___________​(Do not round. Type integers or​ decimals.)

About what percent of autos should get more than 33​mpg?

Using the​ 68-95-99.7 rule, about ____ of autos should get more than 33 mpg ​(Do not round. Type an integer or a​ decimal.)

About what percent of autos should get between 33 and 39.8 mpg?

Using the​ 68-95-99.7 rule, about ________% of autos should get between 33and 39.8 mpg. ​(Do not round. Type an integer or a​ decimal.)

Describe the gas mileage of the best ​2.5% of cars.

Choose the correct answer below.

1. They get more than  33mpg.
2. They get less than 19.4mpg.
3. They get more than 39.8mpg.
4. They get more than 46.6 mpg.