Enter historical parameters for Z-MR Chart

Enter the historical value for the parameters that Minitab uses to calculate the standardized (Z) values. If you do not specify parameters, Minitab estimates the mean and standard deviation from the data. If you enter only one parameter, Minitab estimates the other parameter from the data.

To use historical parameters with a Z-MR chart, the historical mean or standard deviation values must be stored in columns in the worksheet. Columns of parameter values must contain a value for each observation in the data column.

Means

Enter the column containing the mean values for each part.

Standard deviations

Enter the column containing the values of historical standard deviation values for each part.