More Info 32 Ifor Factors for calculating three-sigma limits for the x-chart and R-chart Size of Sample Factor for UCL and LCL for X-chart (A2) Factor for LCL for R-Chart (D3) Factor for UCL for R-Chart (D4) (n) 2 1.880 0 3.267 1.023 0 0.729 0 0.577 0 0.483 oo oo o o 2.575 2.282 2.115 2.004 1.924 1.864 1.816 7 0 0.076 0.136 0.184 0.223 0.419 0.373 0.337 0.308 1.777 Print Done O At Quickie Car Wash, the wash process is advertised to take less than 6 minutes. Consequently, management has set a target average of 320 seconds for the wash process. Suppose the average range for a sample of 7 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 seconds and the LCLR equals 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.)