Using the sample results in Exercise 11.16, construct and interpret the 95% confidence interval for the difference between the population means. Is the hypothesized difference (0.00) within the interval? Given the presence or absence of the 0.00 value within the interval, is this consistent with the findings of the hypothesis test conducted in Exercise 11.16?
In exercise 11.16
An engineer has measured the hardness scores for a sample of conveyor-belt support bearings that have been hardened by two different methods. The first method is used by her company, and the second method is known to be used by a number of other companies in the industry. With the resulting data in file XR11016, use the 0.05 level of significance in comparing the mean hardness scores of the two samples, and comment on the possibility that the difference between the sample means could have occurred by chance. Identify and interpret the p-value for the test.
A computer and statistical software.