document.write( "Question 1206941: Calculate the 95% margin of error in estimating a population mean 𝜇 for the following values. (Round your answer to three decimal places.)
\n" ); document.write( "n = 7,000, s2 = 64
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Algebra.Com's Answer #844735 by Theo(13342)\"\" \"About 
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i believe you want to find the margin of error associated with a 95% confidence interval.\r
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\n" ); document.write( "\n" ); document.write( "you are given tht n = 7000 and s^2 = 64.
\n" ); document.write( "n is the sample size.
\n" ); document.write( "s^2 is the variance.\r
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\n" ); document.write( "\n" ); document.write( "the standard deviation is equal to the square root of the variance = sqrt(64) = 8.
\n" ); document.write( "the standard error is equal to the standard deviation divided by the square root of the sample size = 8 / sqrt(7000) = .0956182887.\r
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\n" ); document.write( "\n" ); document.write( "z-score for 95% confidence interval is z = plus or minus 1.96.\r
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\n" ); document.write( "\n" ); document.write( "the margin of error is equal to (x-m) where x is the critical raw score and m is the mean).\r
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\n" ); document.write( "\n" ); document.write( "on the high side of the confidence interval, the formula becomes 1.96 = (x-m)/s.
\n" ); document.write( "solve for (x-m) to get (x-m) = 1.96 * .0956182887 = .1874118459.\r
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\n" ); document.write( "\n" ); document.write( "on the low side of the confidence interval, the formula becomes -1.96 = (x-m)/s.
\n" ); document.write( "solve for (x-m) to get (x-m) = -1.96 * .0956182887 = -.1874118459.\r
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\n" ); document.write( "\n" ); document.write( "the margin of error is the same.
\n" ); document.write( "it is added to the mean to get the high side of the confidence interval critical raw score (x).
\n" ); document.write( "it is subtract from the mean to get the low side of the confidence interval critical raw score(x).\r
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\n" ); document.write( "\n" ); document.write( "the mean is in the middle to the confidence interval.
\n" ); document.write( "in this type of problem, it can be anything as long as the same standard error is used.\r
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\n" ); document.write( "\n" ); document.write( "for example, if the mean is .5 (randomly chosen), then:\r
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\n" ); document.write( "\n" ); document.write( "the high side of the confidence interval will be 1.96 = (x - .5) / s which becomes 1.96 = (x - .5) / .0956182887.
\n" ); document.write( "solve for x to get b = 1.96 * .095.... + .5 = .6874118459
\n" ); document.write( "your margin of error is .6874118459 minus .5 = .1874118459 which is your desired margin of error.\r
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\n" ); document.write( "\n" ); document.write( "same thing happens on the low side of the confidence interval where the z-score is -1.96.\r
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\n" ); document.write( "\n" ); document.write( "the standard error of .0956182887 is what we had calculated earlier in this analysis.\r
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