Chapter 3, Problem 19E

Consider the call handling limes in Exercise 3.4. Construct a normal probability plot, an exponential probability plot, and a gamma probability plot for these data. IX) any of these distributions seem to be a reasonable probability model for the data? Based on the plots, which distribution is the best one to describe the call handling time?

The Really Cool Clothing Company sells its products through a telephone ordering process. Since business is good, the company is interested in studying the way that sales agents interact with their customers. Calls are randomly selected and recorded, then reviewed with the sales agent to identify ways that belter service could possibly be provided or that the customer could be directed to other items similar to those they plan to purchase that they might also find attractive. Call handling time (length) in minutes for 20 randomly selected customer calls handled by the same sales agent are as follows: 6, 26, 8, 2, 6, 3, 10, 14.4, 5, 3, 17, 9, 8, 9, 5, 3, 28, 21, and 4. Calculate the mean and standard deviation of call handling time.