Question

2- The number of nonconforming switches in Number of Number of samples of size 150 are shown in the Table. Sample Construct a fraction nonconforming control chart (p-chart) for these data. Does the process appear to be in control? If not assume that assignable causes can be found 4 for all points outside the control limits and calculate the revised control limits. Nonconforming Switches Sample Number Nonconforniro Switches Number 12 13 14 15 16 17 18 19 0 15 10

Answer 1

Using Excel<data<megastat<Quality control charts<proportion non conforming<sample size<150

The output is as follows:

Quality Control Process Charts
			Sample size	150
			Number of samples	20
				Proportion defective
			Upper Control Limit, UCL	0.0597
			Center	0.0230
			Lower Control Limit, LCL	0.0000

Question: Construct a fraction nonconforming control chart (p- chart) for these data.

Answer:

Control Chart for the Proportion Defective Sample Proportion Defective HHHHHHH 4-6597 -6-6230 1 2 3 4 5 6 7 8 4-6000 9 10 11 12 13 14 15 16 17 18 19 20 Sample Number

Control? Does the process appear to be in cont Ans From the Control Chart we can say that ath and 17th point is outside 3 0 levels. Hence, proven is not in Control n = 150 (sample Size) in Control L- = 0.023 man do xn Control limits Central Line : ² = 0.02 UCL CUpper control limit) 7 + 3 | A (1-6) Ô•0 9 3+ 3 = 0.0597 LCL Control Limit - 3,(l - = 0.023 - 30.017 150 10.093(1-0.093) 150 The Revised control Chart is Central Line ip = 0.023 Upper Control limit (UCL) 0.093 (1-0.09 ) 0.093 + 3 0.093 (1-0.023) 0.023 5 0 100 Tas it E = 0.06971 Lower Control limit 3 (1-0) . I cannot Ibe Lnegative m

Please do the comment for any doubt or clarification. Thank You!