Question

A national manufacturer of ball bearings is experimenting with two different processes for producing precision ball bearings. It is important that the diameters be as close as possible to an industry standard. The output from each process is sampled and the average error from the industry standard is measured in millimeters. The results are presented next.

The researcher is interested in determining whether there is evidence that the two processes yield different average errors. The population standard deviations are unknown but assumed equal. What is the alternate hypothesis?

A) H₁: µ_A ≤ µ_B

B) H₁: µ_A ≠ µ_B

C) H₁: µ_A = µ_B

D) H₁: µ_A > µ_B

Answer 1

Solution :

Given that ,

The researcher is interested in determining whether there is evidence that the two

processes yield different average errors.

This is the two tailed test .

The alternative hypothesis is ,

B) H₁: µ_A ≠ µ_B