1. Using the appropriate control chart, determine two-sigma control limits for each case: a. An inspector found an average of 3.9 scratches in the exterior paint of each of the automobiles being prepared for shipment to dealers. b. Before shipping lawn mowers to dealers, an inspector attempts to start each mower and notes any that do not start on the first try. The lot size is 100 mowers, and an average of 4 did not start (4 percent). 2. Checkout time at a supermarket is monitored using a mean and a range chart. Six samples of n = 20 observations have been obtained and the sample means and ranges computed: Sample Mean Range Sample Mean Range 3.06 .42 4 3.13 46 3.15 .50 3.06 46 3.11 .41 3.09 45 a. Using the factors in Table 4.2, determine upper and lower limits for mean and range charts. b. Is the process in control? 3. Processing new accounts at a bank is intended to average 10 minutes each. Five samples of four observations each have been taken. Use the sample data iń conjunction with Table 10.2 to construct upper and lower control limits for both a mean chart and a range chart. Do the results suggest that the process is in control? Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 9.8 10.2 10.3 9.7 9.9 9.9 9.8 9.9 10.3 10.2 9.8 9.9 9.9 10.1 10.3 10.1 10.4 10.1 10.5 9.7 40.0 40.4 39.6 40.8 40.0 Totals