16.30 Imperfections in wood panels. The number of imperfections (scratches, chips, cracks, and blisters) in manufactured custom wood cabinet panels is important both to the customer and to the custom builder. To monitor the manufacturing process, each hour for 15 consecutive hours a finished panel 4 feet by 8 feet was selected and inspected for imperfections. The number of imperfections per panel is recorded in the table.
a. Plot the number of defects per panel in a c-chart.
b. Locate the center line for the c-chart.
c. Locate upper and lower control limits for the c-chart. Is the process in control?
d. Conduct a runs analysis for the c-chart. What does this imply?