Auto pistons at Yongpin Zhou's plant in Shanghai are produced in a forging process, and the diameter is a critical factor that must be controlled. From sample sizes of 10 pistons produced each day, the mean and the range of this diameter have been as follows: Day Mean(mm) Range(mm) 1 156.9 4.2 2 153.2 4.6 3 153.6 4.1 4 155.5 5.0 5 156.6 4.5 Construct the 3-sigma x-chart and the 3-sigma R-shart for this dimension, using the data observed in the table above. Also, what if the true diameter mean should be 155 mm and you want this as your center (nominal) line, what would the new X - UCL and X- LCL be?