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?

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Answer 1 · 2018-05-24T08:57:26

See process below

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#