Calculate and and the control limits for the and R control charts shown in Figure 12-A. The sample mean, and range for the first nine subgroups and the data for each sample are given in the bottom of the figure. There are 25 samples of size 4. Therefore K = 25, n = 4. Complete the bottom part of the table and then compute the control limits for both charts. Construct the charts plotting and bar as solid lines and control limits as dashed lines as shown in Figure 12-12. The first four data points have been plotted and the points connected, but are they all correctly plotted? Replot any points that are incorrectly plotted. Plot the rest of the data on the charts and comment on your findings.

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U.C.L L.C AveragesX bar chart 95 30 90 70 LC Ranges IR chart 50 ·3D 20 10 65 75 75 60 706075 80 655080 85 70 55 90 75 75 7565 60 50 60 80 66 65 65 75 80 70 85 75 65 80 85 0 90 86 75 85 90 75 85 0 86 65 65 75 86 70 Sum 2.86 3 20 305 2 6 80 766 Higest 0 010 20 265 20 For sampleSzen of less than seven, there is no lowor control limit for ranges For firat subgroup Sum 55-70+65+66 2.55 FIGURE 12-A