20 samples of size 1,500 were drawn from a manufacturing process and the number of defectives in each sample was counted.The mean sample proportion was .020.The upper control limit for the p chart is:
A)0.0200
B)0.0236
C)0.0199
D)0.0308

Question

Quizplus · Accepted Answer

The upper control limit (UCL) for a p-chart is calculated using the formula: UCL = p̄ + z * sqrt((p̄(1-p̄))/n), where p̄ is the mean sample proportion, z is the z-value for the desired confidence level (typically 3 for 99.73% confidence), and n is the sample size. Substituting the given values: UCL = 0.020 + 3 * sqrt((0.020(1-0.020))/1500) ≈ 0.0308.

20 Samples of Size 1,500 Were Drawn from a Manufacturing