Factors for calculating three-sigma limits for the x-chart and R-chart Size of Sample Factor for UCL and LCL Factor for LCL for Factor for UCL for (n) for X-chart (A2) R-Chart (D3) R-Chart (14) 2 1.880 0 3.267 3 1.023 0 2.575 4 0.729 0 2.282 5 0.577 0 2.115 6 0.483 0 2.004 7 0.419 0.076 1.924 8 0.373 0.136 1.864 9 0.337 0.184 1.816 10 0.308 0.223 1.777 ooooo WN At Quick Car Wash, the wash process is advertised to take less than 6 minutes. Consequently, management has set a target average of 340 seconds for the wash process. Suppose the average range for a sample of 9 cars is 8 seconds. Use the accompanying table to establish control limits for sample means and ranges for the car wash process. Click the icon to view the table of factors for calculating three-sigma limits for the x-chart and R-chart. The UCLR equals 14.53 seconds and the LCLR equals 1.47 seconds. (Enter your responses rounded to two decimal places.) The UCL: equals seconds and the LCL; equals seconds. (Enter your responses rounded to two decimal places.)