Question 612264: A confidence interval estimate for the population mean is given to be (40.45, 49.24). If the standard deviation is 11.159 and the sample size is 35, answer each of the following (show all work):
(A) Determine the maximum error of the estimate, E.
(B) Determine the confidence level used for the given confidence interval.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A confidence interval estimate for the population mean is given to be (40.45, 49.24). If the standard deviation is 11.159 and the sample size is 35, answer each of the following (show all work):
(A) Determine the maximum error of the estimate, E.
The width of the CI is ALWAYS 2*ME.
ME = (49.24-40.45)/2 = 4.395
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(B) Determine the confidence level used for the given confidence interval.
ME = z*s/sqrt(n)
4.395 = z*11.159/sqrt(35)
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11.159z = 4.395*sqrt(35)
z = 2.33
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P(z > 2.33) = normaalcdf(2.33,100) = 0.01
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Confidence level = 98%
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Cheers,
Stan H.
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