Among other quality measures,the quality of an electronic component used in manufacturing stereo speakers is monitored with a control chart.In the last 25 days,daily samples of 60 units resulted in the following number of defective units per sample: 8,4,3,7,6,2,5,3,1,0,7,4,2,0,1,6,2,4,3,1,2,8,5,6,and 0.Determine the appropriate upper and lower control limits for this process.
A)[.029,.091]
B)[.056,.064]
C)[0,.152]
D)[0,.202]

Question

Quizplus · Accepted Answer

The control limits for a p-chart are calculated using the formula: p ± 3√(p(1-p)/n), where p is the average proportion defective and n is the sample size. Here, p = total defects/total samples = 81/1500 = 0.054. The control limits are 0.054 ± 3√(0.054(1-0.054)/60), which results in approximately [0, 0.152].

Among Other Quality Measures,the Quality of an Electronic Component Used