A National Manufacturer of Ball Bearings Is Experimenting with Two

Multiple Choice

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 calculated. The results are presented below: The researcher is interested in determining whether there is evidence that the two processes yield different average errors. Given the following MegaStat printout, what analysis and decision can be made?

A) Reject the null hypothesis and conclude the means are different.
B) Reject the null hypothesis and conclude the means are the same.
C) Fail to reject the null hypothesis at the 1% level of significance.
D) Fail to reject the null hypothesis at the 5% level of significance and conclude the means are different.