A quality engineer who collected process data for 10 subgroups with each subgroup consisting of four samples (n=4) in Table 3 decided to discard data of subgroups 6 and 7. The remaining averages and standard deviations of four samples in each of 8 subgroups are summarized in Table 4 below. Table 4. Subgroup Data 2 3 4 6 7 8 9 Subgroup Average x Standard deviations 1 13.01 0.03 12.99 13.01 0.04 12.99 0.03 5 12.98 0.02 13.00 0.02 13.01 0.04 10 13.01 0.03 0.02 (4-1) Calculate center line 7 of X chart excluding subgroups 6 and 7. Answer Center line of X chart (4-2) Calculate average standard deviations, which is also the center line of s chart, excluding subgroups 6 and 7. Answer Average standard deviations (4-3) Standard deviation 0. Answer Standard deviation on (4-4) Calculate upper control limit (UCL) and lower controllimit (LCL) of X chart excluding subgroups 6 and 7. Answer UCL of X chart LCL of X chart (4-5) Calculate upper controllimit (UCL) and lower control limit (LCL) of s chart excluding subgroups 6 and 7. Answer UCL of s chart LCL of s chart