. A random sample of 8 shipments yielded the following loading times (in hours): 16, 20, 1o, 12, 22, 14, 15, 1s a. Find a 98% condence interval for the mean loading time. Interpret it. (3) b. A process improvement team studied the loading operation and heliele they improved it. A random sample of Ill shipments, after process improvement, showed the following loading times: 13, 8, 10, 12, 14, 8, 10, 7, 11, 10 Find a 99% condence interval for the mean loading time after process improvement. Interpret it. (3) c. Find a 98% condence interval for the di'erence in the mean loading times, before and aer process improvement. What assumptions do you need to make? (3} (1. Test hypothesis to determine if the mean loading time has been reduced after process improvement compared to that before. Use a level of signicance of 0.05. Clearly state the null and alternative hypothesis, the test statistic, the p-value, and your decision. (4) e. Interpret the p-valne. (2}