Question

31.) the piston diameter of a certain hand pump is .7 inch. the manager determines that the diameters are normally distributed, with a mean of .7 inch and a standard deviation of .003 inch. after recalibratinf the production machine, the manager randomly selects 27 pistons and determines that the standard deviation is .0027 inch. is there significant evidence for the manager to conclude that the standard deviation has decreased at the a=.10 level of significance? show work

The piston diameter of a certain hard pump is 0.7 inch. The manager determines that the diameters are normally dibuted with a mean of 0.7 inch and a standard deviation of 0.003 inch. After recalibrating the production machine, the manage randomly selecta 27 pistons and determines that the standard deviation is 0.0027 inch. Is there significant evidence for the manager to conclude that the standard deviation has decreased at the 0.10 level of significance? What are the correctlypotheses for the test? The rul hypothesis is to The weative hypothesis is H, Calculate the value of the test statistic x-Round to two decimal places as needed Une technology to determine the value for the best statistic The Polis (Round to three decimal places as needed) What is the correct conclusion at the 0.10 level of significance? Since the P value is than the level of significance, the rulhypothesis. There sufficient evidence to conclude that the standard deviation has decreased at the 0.10 level of significance

Answer 1

Answer:-

sepi to test null alternative Hypothers Ho: 6 = 0.093 Hir< 0.003 Stepa test statistic, Xo = (n-1) 52 602 2 (29-1) (0.00207 0.003) X = 121.06 difahay = 26 Step3 stepy P- value 0.939 (one tailed Oo 739 Steps Conclusions Since the p-ralue is greater than the level of fail to Reject the null hype thesis, there is not sufficient evidence to conclude that the standard deviation has decreased at the Significan Significance, so we 0:10 level of

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