RANGE 1.2 (6 points): A transmission casing bolt threading process has process mean = 30.48, as shown by the machine and gage measurements for one part in the figure below. (8)= process standard deviation needs to be estimated, USL=41.10, and LSL=18.30. Assume n=5. The subgroups are time intervals. 50- MEAN 40 30- 20- 10- 30- 20- 7:00 8:00 9:00 10:00 H SPEC-41.10 UCL-53-36.33 XBAR-30 48 LCL-53-24.62 L SPEC-18.30 UCL-53-21.44 RBAR-10.14 LCL-53-0.00 7:00 8:00 9.00 10:00 a) What is the potential process capability ratio percentage of this process based on the information provided in the xbar and R charts above? b) What is the actual capability at process subgroup time interval indicated by the circled green dot in the X bar chart (just before time interval 8.00). c) Is this a centered process at the circled green dot (xbar chart)? What about at 9.00? Explain briefly. Dashed lines indicate the 7.00 and 9.00 intervals.