Auto pistons at wemming 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 range of this diameter have been as follows: data from sample pistons day mean 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 what are the uclx-bar lclx-bar using 3-sigma?