5. In order to ensure efficient usage of a server, it is necessary to estimate the mean number of concurrent users. A random sample of 100 times gave a mean of 37.7 users and standard deviation of 9.2 users. At a = 0.10, is there enough evidence that the mean number of concurrent users is more than 32? 6. Out of 260 randomly selected users of a financial application 215 were able to create an expense report using this application. Can it be concluded that the true proportion of users who are able to create an expense report using this application is less than 0.85? Use a = 0.01.1. A manager evaluates effectiveness of a major hardware upgrade by running a certain process 50 times before the upgrade and 50 times after it. Based on these data, the average running time is 8.5 minutes before the upgrade, and 7.2 minutes after it. The sample standard deviations are 1.8 and 1.75, respectively. A. Construct a 90% condence interval for the difference in running time before and after the upgrade. B. At :1 = 0.05, is there enough evidence to conclude that the upgrade has improved average running time