40 samples of size 800 were drawn from a manufacturing process and the number of defectives in each sample was counted.The mean sample proportion was .035.The lower control limit for the p chart is:
A)0.0350
B)0.0155
C)0.0505
D)0.0545

Question

Quizplus · Accepted Answer

The lower control limit for a p chart can be found using the formula:

LCL = p-bar - 3*sqrt(p-bar*(1-p-bar) / n)

where p-bar is the mean sample proportion and n is the sample size.

Substituting the given values, we get:

LCL = 0.035 - 3*sqrt(0.035*(1-0.035) / 800)

LCL = 0.0155

Therefore, the lower control limit for the p chart is 0.0155, which corresponds to option B.

40 Samples of Size 800 Were Drawn from a Manufacturing