8.1 Estimation Using Normal

# Comment on the functioning of the for 001 production

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Unformatted text preview: the population mean is between 10.99 and 11.00 inches. The desired mean is within this interval and we can conclude the production process is working Example 1 Interval Estimation A paper manufacturer has a production process that operates continuously throughout an entire production shift. The paper is expected to have a mean length of 11 inches, and the standard deviation of the length is 0.02 inches. At periodic intervals, a sample is selected to determine whether the mean paper length is still equal to 11 inches or whether something has gone wrong with the production process to change the length of the paper produced. You select a random sample of 100 sheets, and the mean paper length is 10.998 inches. Construct a 95% and a 99% confidence interval estimate for the population mean paper length. Comment on the functioning of the For α=0.01 production process. using CONFIDENCE.NORM (alpha,standard_dev,size) lower: =10.998–CONFIDENCE.NORM (0.01,0.02,100)=10.99284834 upper: =10.998+CONFIDENCE.NORM (0.01,0.02,100)=11.0031516 Therefore, we are 99% confident that the population mean is between 10.9928 and 11.0032 and the process is working correctly. Example 2 One of the few negative side effects of quitting smoking is weight gain. Suppose that the weight gain in the 12 months following a cessation in smoking is normally distributed with a standard deviation of 6 kilograms. To estimate the mean weight gain, a random sample of 13 quitters was drawn their weight gains recorded and listed here. Determine the 90% confidence interval estimate of the mean 12-month weight gain for all quitters. Interval Estimation Example 2 One of the few negative side effects of quitting smoking is weight gain. Suppose that the weight gain in the 12 months following a cessation in smoking is normally distributed with a standard deviation of 6 kilograms. To estimate the mean weight gain, a random sample of 13 quitters was drawn their weight gains recorded and listed here. Determine the 90% confiden...
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## This document was uploaded on 03/05/2014.

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