SOLUTION: A final exam in Statistics has a mean of 73 with a standard deviation of 7.73. Assume that a random sample of 24 students is selected and the mean test score of the sample is comp
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Question 682803: A final exam in Statistics has a mean of 73 with a standard deviation of 7.73. Assume that a random sample of 24 students is selected and the mean test score of the sample is computed. What percentage of sample means are less than 70? Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! A final exam in Statistics has a mean of 73 with a standard deviation of 7.73. Assume that a random sample of 24 students is selected and the mean test score of the sample is computed. What percentage of sample means are less than 70?
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std of the sample means for samples of size 2 is 7.73/sqrt(24)
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z(70) = (70-73)/[7.73/sqrt(24)] = 1.9013
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P(x < 70) = P(z < 1.9013) = normalcdf(-100,1.9013) = 0.9714
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Cheers,
Stan H.
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