A company manufactures rolled steel for nuclear submarines. To monitor the production process, a quality control inspector sampled finished rolls of steel from the production line, one each hour for 12 consecutive hours. The number of imperfections discovered on each roll is recorded in the table.

a. Construct a control chart for the number of imperfections per finished roll of steel.

b. Locate the center line and upper and lower control limits on the chart.

c. Does the manufacturing process appear to be in control?

Transcribed Image Text:

STEELROLL Нour 1 2 3 4 5 6 7 8 9 10 11 12 Number of Imperfections 14 10 8 7 11 12 6 15 13 4 9 10