Factors for calculating three-sigma limits for the x-chart and R-chart Click the icon to view the table of factors for calculating three-sigma limits for the x-chart and R-chart. Assume that only these six samples are sufficient, and use the data to determine control limits for an R - and an x-chart. Compute the range R and the sample mean x for each sample. (Enter your responses rounded to three decimal places.) Factors for calculating three-sigma limits for the x-chart and R-chart Click the icon to view the table of factors for calculating three-sigma limits for the x-chart and R-chart. Assume that only these six samples are sufficient, and use the data to determine control limits for an R - and an x-chart. Compute the range R and the sample mean x for each sample. (Enter your responses rounded to three decimal places.)