In a survey of men in Canada ages 2029 the mean height was 6

In a survey of men in Canada (ages 20-29), the mean height was 68.4 inches with a standard deviation of 3.2 inches.

What height represents the third quartile?

P(X<x)=0.75

--> P((X-mean)/s <(x-68.4)/3.2) = 0.75

--> P(Z<(x-68.4)/3.2) =0.75

--> (x-68.4)/3.2 = 0.67 (from standard normal table)

So x= 68.4 +0.67*3.2 =70.544