Question 1133698: A psychologist finds that the intelligence quotients of a group of patients are normally distributed, with a mean of 92 and a standard deviation of 16. Find the percent of the patients with the following IQs?
(a) above 104
%
(b) between 80 and 110
%
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A psychologist finds that the intelligence quotients of a group of patients are normally distributed, with a mean of 92 and a standard deviation of 16. Find the percent of the patients with the following IQs?
(a) above 104%
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z(104) = (104-92)/16 = 12/16 = 3/4
P(x < 104) = P(z > 3/4) = normalcdf(3/4,100) = 22.66%
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(b) between 80 and 110%
z(80) = (80-92)/16 = -12/16 = -3/4
z(110) = (110-92)/16 = 18/16 = 9/8
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P(80< x <110) = normalcdf(-3/4,9/8) = 0.6431
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Cheers,
Stan H.
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