Question 257391: The heights of 1000 girls at East High School were measured, and the mean was found to be 64 in., with a standard deviation of 2 in. If the heights are approximately normally distributed, about how many of the girls are between 60 and 64 in. tall?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! The heights of 1000 girls at East High School were measured, and the mean was found to be 64 in., with a standard deviation of 2 in. If the heights are approximately normally distributed, about how many of the girls are between 60 and 64 in. tall?
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Find the z-scores of 60 and 64.
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z(60) = (60-64)/2 = -4/2 = -2
z(64) = (64-64)/2 = 0
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P(60 < x < 64) = P(-2 < z < 0) = 0.4772...
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# of girls between 60 and 64 is approx 0.4772*1000 = 477
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Cheers,
Stan H.
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