Refer to Table S6.1 - Factors for Computing Control Chart Limits (3 sigma) for this problem. Auto pistons at Wenming Chung'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: E Mean x Range R Day (mm) (mm) 1 154.9 4.4 2 153.2 4.8 3 151.6 4.1 45 157.5 5.2 156.6 4.3