A manufacturer wants to determine if two testers yield to similar response. Ten parts were measured on machine A and another 10 parts were measured on machine B.
Machine A: 147.3, 153.0, 140.3, 161.0, 145.1, 145.0, 150.1, 158.7, 154.9, 152.8
Machine B: 149.6, 155.5, 141.3, 162.1, 146.7, 145.5, 151.6, 159.3, 154.8, 152.7
(a) Determine if there is a statistically significant difference in the mean response at a level of 0.05.
(b) If the data were collected such that 10 parts were evaluated on each of the two machines with the pairing as noted. For example, the first part yielded a value of 147.3 on machine A, while it yielded 149.6 on machine B. Determine if there is a statistically significant difference in the mean.
(c) For the paired evaluation, use a normal probability plot to pictorially quantify the best estimate for the difference that would be expected 80% of the time. Determine the value using a Z table (i.e. Table A in Appendix E).