Methods and formulas for graphs in Normal Capability Analysis for Multiple Variables

The histogram is displayed with two normal curves.

Black dashed curve

This normal distribution is generated using the process mean and the within-subgroup standard deviation.

Red solid curve

This normal distribution is generated using the process mean and the overall standard deviation.

For information on how the standard deviations are calculated, go to Methods and formulas for methods used in Normal Capability Analysis and click "Estimating standard deviation".

For information on the calculations used to create the normal probability plots, go to Methods and formulas for probability plot in Individual Distribution Identification.