Refer to Exercise 16.11. Suppose the inspector wants to monitor the variation in firing pin lengths with

Question:

Refer to Exercise 16.11. Suppose the inspector wants to monitor the variation in firing pin lengths with an R-chart.

a. Locate the center line for the R-chart.

b. Locate upper and lower control limits for the R-chart.

c. Calculate and plot the 10 sample ranges in an R-chart. Does the process variation appear to be in control?

Data from Exercise 16.11

A corporation that manufactures field rifles for the Department of Defense operates a production line that turns out finished firing pins. To monitor the process, an inspector randomly selects five firing pins from the production line, measures their lengths (in inches), and repeats this process at 30-minute intervals over a 5-hour period.