The average gas mileage of a certain model car is 28.0 miles per gallon. If the gas mileages are normally distributed with a standard deviation of 0.45 miles per gallon, find the probability that a car has a gas mileage of between 27.8 and 28.2 miles per gallon.
A) 0.343
B) 0.157
C) 0.403
D) 0.172

Question

Quizplus · Accepted Answer

The probability that a car has a gas mileage of between 27.8 and 28.2 miles per gallon is the area under the normal distribution curve between z-scores of -0.44 and 0.44. This area is 0.343.

The Average Gas Mileage of a Certain Model Car Is