SOLUTION: The standard IQ test is designed so that the mean is 100 and the standard deviation is 15 for the population of all adults. We wish to find the sample size necessary to estimate

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Question 438690: The standard IQ test is designed so that the mean is 100 and the standard deviation is 15 for the population of all adults. We wish to find the sample size necessary to estimate the mean IQ score of statistics students. Suppose we want to be 90 % confident that our sample mean is within 2 IQ points of the true mean. Assume then that sigma is 15 and determine the required sample size.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The standard IQ test is designed so that the mean is 100 and the standard deviation is 15 for the population of all adults. We wish to find the sample size necessary to estimate the mean IQ score of statistics students. Suppose we want to be 90 % confident that our sample mean is within 2 IQ points of the true mean. Assume then that sigma is 15 and determine the required sample size.
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n = [zs/E]^2
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n = [1.645*15/2]^2 = 153 when rounded up
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Cheers,
Stan H.
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