C. What comments can you make about the process? [15 Marks] [2 marks] [TOTAL: 25 MARKS] QUESTION SIX A. Explain what is meant by process capability. Why is it important? What does it tell us? How can it be measured (You should give equations used to calculate Cp and Cok)? [10 Marks] B. In the manufacture of vitamin capsules, the proportion of calcium in each capsule has a specification of 48 + 18 parts per million (ppm). A random sample of 100 capsules revealed a sample average calcium content of 44.5 ppm and a standard deviation of 3.2 ppm. Management also uses i and R- charts to monitor the calcium amount using samples of size 4. The charts depict an in-control process. The centerline of the R chart is 6.7 and the centerline of the i chart is 44.8. 1. II. III. Compute Cp for this process using estimates of the process mean and standard deviation derived from the random sample [2 marks] Compute Cp for this process using estimates of the process mean and standard deviation derived from the control chart data [2 marks] Compute Cpk for this process using estimates of the process mean and standard deviation derived from the control chart data. [4 Marks] Compute Cpk for this process using estimates of the process mean and standard deviation derived from the control chart data. [4 Marks] What do the differences between the values of Cp and Cpk tell you? [3 Marks] IV. V. ITOTAL: 25 MARKS] END OF EXAMINATION PAPER Page 7 of 9