As reported in "Runner's World" magazine, the times of the finishers in the New York City 10 km run are normally distributed with a mean of 61 minutes and a standard deviation of 9 minutes. Let x denote finishing time for the finishers. a) The distribution of the variable x has mean and standard deviation .b) The distribution of the standardized variable z has mean and standard deviation .c) The percentage of finishers with times between 40 and 65 minutes is equal to the area under the standard normal curve between and .d) The percentage of finishers with times exceeding 69 minutes is equal to the area under the standard normal curve that lies to the of .