One of steel cable's key characteristics is tensile strength in PSI. The data listed below gives tensile strength for steel cable used in constructing bridges. Because the cable is manufactured in a continuous process, the best type of chart to use to monitor the production process is a moving average, moving range chart.
As the cable is made, a sample is taken every half-hour. Use n = 3 and the following information to create a moving average and a moving range chart. Work to whole numbers.
What are the upper & lower control limits for Xbar, R, & S?
42,000
47,000
46,000
48,000
45,000
47,000
45,000
41,000
48,000
51,000
49,000
46,000