Enter the historical values for the parameters that Minitab uses to calculate the center line and control limits. If you do not enter values, Minitab estimates the mean and the standard deviation from the data. If you enter only one value, Minitab estimates the other parameter from the data.
- Mean
- You can enter a single mean for the entire chart, or you can enter a mean for each stage. The mean is used to calculate the center line on the I chart.
- Standard deviations
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- Between subgroups
- You can enter a single between subgroups standard deviation for the entire chart, or you can enter a standard deviation for each stage. The standard deviation is used to calculate the center line and the control limits on the MR chart and the control limits on the I chart.
- Within subgroups
- You can enter a single within subgroups standard deviation for the entire chart, or you can enter a standard deviation for each stage. The standard deviation is used to calculate the center line and control limits on the R or S chart.
