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? Please include interpretation of the 90% CI you have calculated in your answer.