A p chart is to be developed for use in quality control.The value of p is calculated to be 0.05.The sample size is 50.What would the upper control limit be?
A)0.142
B)-0.042
C)0.408
D)0.092
E)0.642

Question

Quizplus · Accepted Answer

The upper control limit (UCL) for a p-chart is calculated using the formula UCL = p + Z√(p(1-p)/n), where p is the proportion of defectives, Z is the Z-value from the standard normal distribution for the desired confidence level (commonly 3 for control charts), and n is the sample size. For p = 0.05, n = 50, and using a Z-value of 3 (for a common confidence level of 99.73% in control charts), UCL = 0.05 + 3√(0.05*0.95/50) ≈ 0.142.

A P Chart Is to Be Developed for Use in Quality