Question

An automobile manufacturer introduces a new model that averages 27 miles per gallon in the city. A person who plans to purchase one of these new cars wrote the manufacturer for the details of the tests, and found out that the standard deviation is 3 miles per gallon. Assume that in-city mileage is approximately normally distributed. What is the probability that the person will purchase a car that averages less than 20 miles per gallon for in-city driving

Answer 1

Given :

An automobile manufacturer introduces a new model that averages 27 miles per gallon in the city.

Standard deviation , S.D = 3 miles per gallon .

To Find :

The probability that the person will purchase a car that averages less than 20 miles per gallon for in-city driving.

Solution :

We have to find the probability ,
`P(X\leq 20)` .

Here , we will use the excel function

So ,

`P(X\leq 20)=NORMADIST( 20, 27 , 3 , 1 )=0.009815` .

Therefore , probability is 0.009815 .