SOLUTION: An organization is trying to determine the mean IQ of professional pilots. How large a sample is required if they want to be 98% confident that the sample mean is within 4 IQ pts.

Question 1030508: An organization is trying to determine the mean IQ of professional pilots. How large a sample is required if they want to be 98% confident that the sample mean is within 4 IQ pts. of the population mean. Suppose you can assume that the standard deviation of pilot IQs is the same as the standard deviation of IQs for all adults, which is 15.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
An organization is trying to determine the mean IQ of professional pilots. How large a sample is required if they want to be 98% confident that the sample mean is within 4 IQ pts. of the population mean. Suppose you can assume that the standard deviation of pilot IQs is the same as the standard deviation of IQs for all adults, which is 15.
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Since E = z*s/sqrt(n),
n = [zs/E]
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n = [2.3263*15/4]^2 = 76 when rounded down
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Cheers,
Stan H.
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