Hi,

I am trying to figure out differences in LCL for 2 different P charts. For one chart I see LCL = 0 (which does make sense) and for the other chart I see LCL varying (but above zero), which also makes sense. For both cases I have a column with the total and another with the number of defectives, the total column is used for sample size when making both charts. The only difference seems to be the sample sizes (total) is bigger for one chart.