document.write( "Question 137926: 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. \n" ); document.write( "
Algebra.Com's Answer #100794 by stanbon(75887)\"\" \"About 
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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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\n" ); document.write( "(n-1)s^2/(Ch-Sq right) = 35
\n" ); document.write( "26*s^2/41.923 = 35
\n" ); document.write( "s^2 = 35*41.923/26
\n" ); document.write( "s^2 = 56.434
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\n" ); document.write( "(n-1)s^2/(Ch-Sq left) = 88.4
\n" ); document.write( "26*s^2/15.379 = 88.4
\n" ); document.write( "s^2 = 88.4*15.379/26
\n" ); document.write( "s^2 = 52.2886
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\n" ); document.write( "The discrepancy is probably due to my Ch-Sq table truncating its values.
\n" ); document.write( "It gives the Ch-Sq. left and right values as indicated. Your chart
\n" ); document.write( "may give values with greater decimal precision.
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.\r
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