9. Measurements of the diameters of a random sample of 13 ball bearings made by machine X during one week showed a mean of 8.22 mm and a standard deviation of 0.38 mm. However, other measurements of the diameters ofa random sample of 11 ball bearings made by machine Y during the same week showed a mean of 7.68 mm and a standard deviation of 0.42 mm. Assuming the diameters are normally distributed with equal variance, a) Construct a 99% confidence interval for the difference in the true mean diameters of ball bearings made by the two machines. b) Based on your answer in part (a), are you 99% confident that the true mean diameters of ball bearings made by machines X and Y are not equal? Justify your answer.

9. Measurements of the diameters of a random sample of 13 ball bearings made by machine X during one week showed a mean of 8.22 mm and a standard deviation of 0.38 mm. However, other measurements of the diameters ofa random sample of 11 ball bearings made by machine Y during the same week showed a mean of 7.68 mm and a standard deviation of 0.42 mm. Assuming the diameters are normally distributed with equal variance, a) Construct a 99% confidence interval for the difference in the true mean diameters of ball bearings made by the two machines. b) Based on your answer in part (a), are you 99% confident that the true mean diameters of ball bearings made by machines X and Y are not equal? Justify your answer.

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

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