P8 The diameter of a ball hearing was measured by 12 inspectors, each using two different kinds of calipers. The results were Inspector Caliper l Caliper 2 I 0.265 0.264 2 0.265 0.265 3 0.266 0.264 4 0.267 0.266 5 0.267 0.267 6 0.265 0.268 7 0.267 0.264 8 0.267 0.265 9 0.265 0.265 [O 0.268 0.267 I I 0.268 0.268 [2 0.265 0.269 (a) Is there a signicant difference between the means of the population of measurements from which the two samples were selected? Use a = 0.05. (1)) Find the P-value for the test in part (a). (c) Construct a 95 percent condence interval on the dif- ference in mean diameter measurements for the two types of calipers