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 , [tex]P(X\leq 20)[/tex] .
Here , we will use the excel function
So ,
[tex]P(X\leq 20)=NORMADIST( 20, 27 , 3 , 1 )=0.009815[/tex] .
Therefore , probability is 0.009815 .