Suppose that arrival times for an elevator in a large hotel are bell-shaped and symmetric with a mean of 20 seconds and a standard deviation of 6 seconds. (a) Approximately 68% of arrival times are between what two values? and (b) What percent of the time will the elevator arrive between 8 and 32 seconds? (c) What percent of the time will the elevator arrive in less than 2 seconds? (d) What percent of the time will the elevator arrive in more than 8 seconds? (e) What percent of time will the elevator arrive between 8 seconds and 38 seconds? (f) What percent of time will the elevator arrive between 2 seconds and 8 seconds? (g) What percent of time will the elevator arrive between 26 seconds and 38 seconds