Q2 - Process capability indices using subgroup averages and ranges A quality engineer collected process data for five subgroups with each subgroup consisting of four samples (n=4). The averages and ranges of samples in each subgroup are summarized in Table 2 below. The upper specification limit (USL) of the process is 13.10 and the lower specification limit (LSL) is 12.90. Table 2. Subgroup Data Subgroup 1 2 3 5 Average X 13.00 12.97 12.96 12.98 12.99 Range R 0.06 0.04 0.03 0.04 0.03 (2-1) Calculate the average X of subgroup averages X. Answer X (average of subgroup averages X) (2-2) Calculate the average R of subgroup ranges R. Answer R (average of subgroup ranges R) (2-3) Calculate the estimate o of population standard deviation. Answer (estimate of population standard deviation) (2-4) Calculate the process capability index Cp. Answer Cp (2-5) Answer questions in the below table on this process. Answer Is this process capable in terms of Cp? Yes or No Briefly explain reason of your above Explain answer (2-6) Calculate the process capability index Cpk. Answer Cpk (2-7) Answer questions in the below table on this process. Answer Is this process capable in terms of Cpk? Yes or No Briefly explain reason of your above Explain