8.2 A Single Population Mean using the Student t Distribution Use the following information to answer the next five exercises. A hospital is trying to cut down on emergency room wait times. It is interested in the amount of time patients must wait before being called back to be examined. An investigation committee randomly surveyed 70 patients. The sample mean was 1.5 hours with a sample standard deviation of 0.5 hours. 38. Identify the following: I = Si n n 1 39. Define the random variables X and X in words. 40. Which distribution should you use for this problem? 41 . Construct a 95% confidence interval for the population mean time spent waiting. State the confidence interval, sketch the graph, and calculate the error bound. 42. Explain in complete sentences what the confidence interval means.