Sixty samples of size 600 each were drawn from a manufacturing process and the number of defectives in each sample was counted. The average sample proportion was 0.04. The lower control limit for the p chart is:
A) 0.008
B) 0.016
C) 0.064
D) 0.048
E) 0.032

Question

Quizplus · Accepted Answer

The lower control limit (LCL) for a p chart is calculated using the formula: LCL = p̄ - 3√(p̄(1-p̄)/n), where p̄ is the average sample proportion and n is the sample size. Here, p̄ = 0.04 and n = 600. LCL = 0.04 - 3√(0.04(1-0.04)/600) = 0.016.

Sixty Samples of Size 600 Each Were Drawn from a Manufacturing