Dave C.
asked • 06/06/21You measure 49 textbooks' weights, and find they have a mean weight of 65 ounces.
Assume the population standard deviation is 8.9 ounces. Based on this, construct a 99% confidence interval for the true population mean textbook weight.
Give your answers as decimals, to two places
_______ < μ < _________
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1 Expert Answer
Chris D. answered • 06/13/21
Tutor
4.9
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Math Specialist BU and BC grad
The 99% confidence interval is the sample mean plus or minus the z star times the standard error. the z scores that will capture the middle 99% of a normal curve is -2.58 to 2.58 and the standard error is sigma/sqrt(49) so the confidence interval is 65 +/- (2.58)(8.9/sqrt(49) which gives 61.73< Mu<68.27
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Chris D.
the 99% confidence interval is the sample mean plus or minus the z star times the standard error. the z scores that will capture the middle 99% of a normal curve is 2.58 and the standard error is sigma/sqrt(49) so xbar of 65 +/- (2.58)(8.9/sqrt(49) gives 61.73< Mu<68.2706/13/21