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P ChartStat > Control Charts > Attributes Charts > P
Tracks the proportion defective and detects the presence of special causes. Each entry in the worksheet column is the number of defectives for one subgroup, assumed to have come from a binomial distribution with parameters n and p.
If your data exhibit overdispersion or underdispersion a Laney P' chart may more accurately distinguish between common cause variation and special cause variation.
For more information, see Control Charts Overview and Attributes Control Charts Overview.
Variables: Enter columns that contain the number of defectives for each sample.
Subgroup sizes: Enter a number or a column containing the subgroup sizes. If the subgroups are not equal, each control limit is not a single straight line but varies with the subgroup size. If the subgroup sizes do not vary much, you may want to force the control limits to be constant by specifying a fixed subgroup size using P Chart Options > Limits.