Q3a) Punctuality of patients in keeping appointments is of interest to a research team. In a study of patient flow through the offices of general practitioners, it was found that a sample of 35 patients were 17.2 minutes late for appointments, on the average. Previous research had shown the standard deviation to be about 8 minutes. The population distribution was felt to be non-normal. What is the 90 percent confidence interval for , the true mean amount of time late for appointments?

b)We wish to estimate the average number of heart-beats per minute for a certain population with the confidence interval of 95 percent. The average number of heart-beats per minute for a sample of 49 subjects was found to be 90. Assume that these 49 patients constitute a random sample, and that the population is normally distributed with a standard deviation of 10.