Kaminsky et al. (1992) present data on the number of orders per truck at a distribution center. Some of these data are sown in Table 7E.24.

(a) Set up a c chart for the number of orders per truck. Is the process in control?
(b) Set up a t chart for the number of orders per truck, assuming a geometric distribution with a = 1. Is the process in control?
(c) Discuss the findings from parts (a) and (b). Is the Poisson distribution a good model for these data? Is there evidence of this in the data?

TABLE 7E.24 Number of Orders per Truck for Exercise 7.82 No of No. of No. of No. of Truck Orders Truck Orders Truck Orders Truck Orders 5 17 2 58 10 26 18 35 26 1 1 22 6 7 1 219 6 27 9 4 39 1226 20 23 28 21 713 10 2 10 29 6 33 143 217 30 12 5 23 8 23 16 424 10 32 S 5 7 8 15 7 31 4