1)

i. Assuming a 9:3:1 three class weighting system (critical, major, minor), determine the central line and control limits when uoc= 0.08, uoma= 0.5 & uomi= 3.0 and n = 40.

ii. Calculate the demerits per unit for 25th May when critical non conformities are 2, major nonconformities are 26 and minor non conformities are 160 for the 40 units inspected on that day. Is the 25th May subgroup in control or out of control?