2. T20-03 - 1 T20-03 P Chart Control Limit Calculations Purpose Allows the analyst to calculate the proportion "P-Chart" 3-sigma control limits. Inputs Sample Size Centerline (Phat) Outputs P (Proportion) Control Chart LCL & UCL

3. T20-03 - 2 The P-Chart measures the proportions in a process. The Proportion Chart Centerline, UCL and LCL are calculated by the following formula. Standard Error P-Chart (Proportion Chart)

4. T20-03 - 3 The proportion of 20 samples each containing 100 observations are shown here. The average proportion (Phat) can now be calculated. This can be done by using the Descriptive Statistics Template or more quickly by using the EXCEL built in AVERAGE function on this set of numbers. Calculate the Control Limits for the Mean Control Chart. Example Average Proportion

5. T20-03 - 4 Input the Sample Size, and Average Proportion (Phat) in the light green cells. The LCL, UCL are automatically calculated