20. The following data were used to construct the histograms of the number of days required to fill orders for Dawson Supply, Inc., and J.C. Clark Distributors (see Figure 3.2).

Dawson Supply Days for Delivery: 11 10 9 10 11 11 10 11 10 10 Clark Distributors Days for Delivery: 8 10 13 7 10 11 10 7 15 12 Use the range and standard deviation to support the previous observation that Dawson Supply provides the more consistent and reliable delivery times.