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The average height for males is normally distributed with a mean of 70in. and a...
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High School Teacher
Probability density function for normal random variable is
In your case `sigma=4.5` and `mu=70` so your function is
You are looking for 25th percentile. For that you need to find solution to the equation
where `Phi` is cumulative distribution function of your random variable that is
Hence, you need to find solution to the equation
`1/(4.5sqrt(2pi))int_-oo^x e^(-(x-70)^2/(2cdot4.5^2))=0.25` (2)
Since there are no elementary function corresponding to `Phi` the equation must be solved numerically.
Solution to equation (2) is `x approx 66.9648`.
So the man is about 70 inches (66.9648in to be exact) tall.
Posted by tiburtius on April 23, 2013 at 6:47 PM (Answer #1)
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