SOLUTION: A 90% confidence interval around the variance was calculated. For n = 27 , the confidence interval was 35.0�88.4. Give the variance of the sample.

Question 1040407: A 90% confidence interval around the variance was calculated. For n = 27 , the confidence interval was 35.0�88.4. Give the variance of the sample.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
A 90% confidence interval around the variance was calculated. For n = 27 , the confidence interval was 35.0�88.4. Give the variance of the sample.
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The width of the CI is 2*ME
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Your Problem::
2*ME = (88.4-35) = 53.4
ME = 26.7
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ME = z*s/sqrt(n)
26.7 = 1.645*s/sqrt(27)
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1.645*s = 26.7*sqrt(27) = 138.74
s = 84.34
Ans: variance = s^2 = 84.34^2 = 7113.23
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Cheers,
Stan H.
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