SOLUTION: A quality control expert is called in to determine whether a newly installed machine is producing a particular cotton cloth according to the specifications set by the manufacturer.

Question 208293: A quality control expert is called in to determine whether a newly installed machine is producing a particular cotton cloth according to the specifications set by the manufacturer. The mean warp-breaking strength of this particular cotton cloth has been established to be 66 pounds. A random sample of 36 pieces of cotton cloth is obtained from a production run on this machine. The results of the sample reveal a mean warp-breaking strength of 64.5 pounds and a standard deviation of 5 pounds. Can the quality control expert say that the cotton produced on the new machine meets the warp-breaking specification of the manufacturer at the .05 level of significance?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
The mean warp-breaking strength of this particular cotton cloth has been established to be 66 pounds. A random sample of 36 pieces of cotton cloth is obtained from a production run on this machine. The results of the sample reveal a mean warp-breaking strength of 64.5 pounds and a standard deviation of 5 pounds. Can the quality control expert say that the cotton produced on the new machine meets the warp-breaking specification of the manufacturer at the .05 level of significance?
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Ho: u >= 66
Ha: u < 66
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I ran a T-test and got the following:
test statistic: t = -1.8
p-value: 0.0402
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Conclusion: Since the p-value is less than 5%, reject Ho.
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Cheers,
stan H.
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