Consider results of 20 randomly chosen people who have run a marathon. Their times, in minutes, are as follows: 136, 143, 152, 165, 171, 178, 184, 195, 196, 205, 219, 221, 232, 239, 256, 267, 275, 281, 284, 289. Calculate a 95% upper confidence bound on the mean time of the race. Assume distribution to be normal. Round your answer to the nearest integer (e. g. 9876).