Question

In a survey of men in the United States (ages 20-29), the mean height was 69.6 inches with a standard deviation of 3.0 inches. If 320 men are randomly selected, about how many of them are taller than 71 inches?

Thanks in advance

Answer 1

See process below

Explanation:

The data follow a Normal distribution `N(69.6;3)`

Let be `X=`height of men

We have to find `P(X>=71)` and result will be multiply by 320

`P(X>=71)=1-P(X<71)=1-P(Z<(71-69.6)/3)=1-P(Z<0.467)=1-0.6772=0.3228`

Then `N=320·0.3228=103`