Reference Factors for calculating three-sigma limits for the x-chart and R-chart Factor for LCL for R-Chart (D3) 0 Factor for UCL for R-Chart (D4) Size of Sample Factor for UCL and LCL (n) for X-chart (A2) 2 1.880 3 1.023 4 0.729 5 0.577 6 0.483 7 0.419 8 0.373 9 0.337 10 0.308 0 0.076 0.136 0.184 0.223 3.267 2.575 2.282 2.115 2.004 1.924 1.864 1.816 1.777 The Money Pit Mortgage Company is interested in monitoring the performance of the mortgage process. Fifteen samples of five completed mortgage transactions each were taken during a period when the process was believed to be in control. The times to complete the transactions were measured. The means and ranges of the mortgage process transaction times, measured in days, are as follows: 2 3 4 7 8 Sample Mean Range 1 18 5 16 10 10 3 19 7 5 14 8 6 14 13 17 11 18 14 9 15 9 10 16 9 11 17 9 12 11 5 13 13 8 8 14 11 10 15 14 12 Subsequently, samples of size 5 were taken from the process every week for the next 10 weeks. The times were measured and the following results obtained: O 19 21 22 23 Sample Mean Range 16 17 14 16 6 10 18 11 5 17 20 19 11 21 12 15 10 24 9 24 25 22 20 7 5 3 Click the icon to view the table of factors for calculating three-sigma limits for the x-chart and R-chart. a. Construct the control charts for the mean and the range, using the original 15 samples. Set up the R-chart by specifying the center line and three-sigma control limits below. (Enter your responses rounded to two decimal places.) R-chart UCLR = R LCLR = =