A hospital administration wants to estimate the mean time spent by patients waiting for treatment at the emergency room. The waiting times (in minutes) recorded for a random sample of some patients are given below. The population standard deviation is not known. 20, 17, 48, 70, 47, 60, 51, 64, 25, 35, 29, 30, 35, 62, 96, 104, 58, 32, 35, 102, 27, 50, 21, 64, 62, 72, 39, 92, 84, 47, 12, 33, 55, 80, 36. Construct a 95% confidence interval for the corresponding population mean.