Question 1043272: The distribution of cholesterol level in teenage boys is approximately normal with a mean of 170 and a standard deviation of 30. Levels above 200 warrant attention. What percent of teenage boys have levels between 170 and 225?
options were :56.13%, 3.36%, 6.06% and 46.64%
I picked 46.64% but I got it wrong. I don't get it.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! The distribution of cholesterol level in teenage boys is approximately normal with a mean of 170 and a standard deviation of 30. Levels above 200 warrant attention. What percent of teenage boys have levels between 170 and 225?
options were :56.13%, 3.36%, 6.06% and 46.64%
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z(170) = (170-170)/30 = 0
z(225) = (225-170)/30 = 55/30 = 1.83333
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P(170< x < 225) = P(0< z < 5/3) = normalcdf(0,1.8333) = 46.64%
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Comment:: Actually I got an answer of 46.67% when rounded up
But maybe you are supposed to use a chart that gives you an answer of 46.64%
Cheers,
Stan H.
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