Because the corrective action was taken to eliminate the special cause of variation, Natal
Because the corrective action was taken to eliminate the special cause of variation, Natalie removes the data for batch 17 from the analysis. The control charts for the remaining days indicate a stable system, with only common causes of variation operating on the system. Then, Natalie and Jim sit down with Dave Martin and several other machinists to try to determine all the possible causes for the existence of oversized and scrapped rollers. Natalie is still troubled by the data. After all, she wants to find out whether the process is giving oversizes (which are downgraded) and undersized (which are scrapped). She thinks about which tables and charts might be most helpful.
a. Construct a frequency distribution and a stem-and-leaf display of the cam roller diameters. Which do you prefer in this situation?
b. Based on your results in (a), construct all appropriate charts of the cam roller diameters.
c. Write a report, expressing your conclusions concerning the cam roller diameters. Be sure to discuss the diameters as they relate to the specifications.