A pipes manufacturer makes pipes with a length that is supposed to be 15

inches. A quality control technician sampled 39

pipes and found that the sample mean length was 15.04

inches and the sample standard deviation was 0.17

inches. The technician claims that the mean pipe length is not 15

inches.

What type of hypothesis test should be performed?

What is the test statistic?

What is the number of degrees of freedom?

Does sufficient evidence exist at the =0.01

significance level to support the technician's claim?

Select

Left-tailed z-test

Left-tailed t-test

Two-tailed t-test

Two-tailed z-test

Select

No

Yes

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