Refer to Table 56.1 - Factors for Computing Control Chart Limits (3 sigma) for this problem. Twelve samples, each containing five parts, were taken from a process that produces steel rods at Emmanual Kodzi's factory. The length of each rod in the samples was determined. The results were tabulated and sample means and ranges were computed. The results were: Sample Sample Sample Mean (in.) Range (in.) 1 7 8 2 3 Sample Mean (in.) 13.600 13.604 13.593 13.608 13.595 13.599 Range (in.) 0.044 0.051 0.042 0.037 0.048 0.053 9 13.601 13.607 13.597 13.601 13.603 13.604 0.021 0.058 0.039 0.038 0.054 4 5 6 10 11 12 0.061 = For the given data, the x = inches (round your response to four decimal places). Sample Size, n Lower Range, Dz 2 0 3 0 0 4 5 6 0 Mean Factor, A2 1.880 1.023 0.729 0.577 0.483 0.419 0.373 0.337 0.308 0.266 Upper Range, D4 3.268 2.574 2.282 2.115 2.004 1.924 1.864 1.816 1.777 1.716 7 8 0 0.076 0.136 0.184 0.223 0.284 9 10 12 a) Determine the upper and lower control limits and the overall means for -charts and R-charts. b) Draw the charts and plot the values of the sample means and ranges. c) Do the data indicate a process that is in control? d) Why or why not