Question

The body mass indices of American men between ages 30 and 50 are normally distributed with a mean of 26.2 and a standard deviation of 4.7. Several health organizations have declared that men with a BMI of 25 or greater are
overweight and that men with a BMI of 30 or greater are obese. According to these values, what percentage of American men are obese?

Answer 1

Do you know how to find z-scores? Find the z-score for 30,using the given mean and standard deviation.

Answer 2

P(x> 30) =?
just put it in calculator.

Answer 3

Z-score = ( value - mean ) / standard deviation

P ( x > 30 ) = 1 - 0.8106 = 0.1894

Answer 4

x-m/standard deviation

Answer 5

30-26.2/4.7

Answer 6

where did you get 0.8106

Answer 7

I took it from z-score table
http://math.tutorvista.com/statistics/z-score-table.html

Answer 8

ok I got a different answer. I took 30-26.2/4.7=.810
On the z score table that gave me 0.7910
1-0.7910= 20.9%

Answer 9

That looks right^ and reemj didn't show much work so...

Answer 10

yup, I got the same answer on my calculator.