Question

A manufacturing company is measuring the diameter of a ball bearing in mm by 12 inspectors, each using two different kinds of calipers to test the difference between the sample means of the two calipers used. Data is shown below. Use Excel to resolve.

a) Use 2 pair t-test to check if there is a significant difference between the means of the population of measurements from which the two samples were selected? Use α = 0.01, 0.05, 0.1 and comment on the results.

b) Find the P-value for the test in part (a).

Inspector	Caliper 1	Caliper 2
1	0.473	0.518
2	0.512	0.552
3	0.518	0.545
4	0.492	0.521
5	0.484	0.511
6	0.512	0.492
7	0.513	0.558
8	0.536	0.545
9	0.481	0.5
10	0.533	0.575
11	0.536	0.554
12	0.538	0.515

Answer 1