a. 1. List Shewhart’s two types of variation. What are they also called?
2. Define “in statistical control.”
3. Explain briefly what an -chart and an R -chart do.
4. What might cause a process to be out of control?
5. List five steps in developing and using -charts and R -charts.
b. 1. List some possible causes of assignable variation.
2. Explain how a person using 2-sigma control charts will more easily find samples “out of bounds” than 3-sigma control charts. What are some possible consequences of this fact?
3. When is the desired mean, μ, used in establishing the centerline of a control chart instead of ?
4. Can a production process be labeled as “out of control” because it is too good? Explain.