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 transaction: were measured. The means and ranges of the mortgage process transaction times, measured in days, are as follows: 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: 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.) b. On the control charts developed in part (a), plot the values from samples 16 through 25 and comment on whether the process is in control. Choose the correct R-chart for the data below. Choose the correct x-chart for the data below. A. B. C. D. The entire process is control. c. In part (b), if you concluded that the process was out of control, would you attribute it to a drift in the mean, or an increase in the variability, or both? The process variability is statistical control and the process average is statistical control. Therefore, the entire process is control. Reference Factors for calculating three-sigma limits for the x-chart and R-chart