SOLUTION: The achievement scores for a college entrance examination are normally distributed with a mean of 75 and a standard deviation of 10. What fraction of the scores would you expect to
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Question 824481: The achievement scores for a college entrance examination are normally distributed with a mean of 75 and a standard deviation of 10. What fraction of the scores would you expect to lie between 70 and 90? Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! The achievement scores for a college entrance examination are normally distributed with a mean of 75 and a standard deviation of 10. What fraction of the scores would you expect to lie between 70 and 90?
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z(90) = (90-75)/10 = 15/10 = 1.5
z(70) = (70-75)/10 = -5/10 = -1/2
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P(70< x <90) = P(-1/2 < z < 1.5) = normalcdf(-1/2,1.5) = 0.6247
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Cheers,
Stan H.
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