A p chart is to be developed for use in quality control.The value of p is calculated to be 0.04.The sample size is 100.What would the upper control limit be?
A)0.059
B)0.099
C)0.109
D)0.040
E)1.090

Question

Quizplus · Accepted Answer

The upper control limit for a p chart is calculated using the formula:
UCL = p + 3√[p(1-p)/n]
where p is the proportion of defects, n is the sample size.
Substituting the given values, we get:
UCL = 0.04 + 3√[0.04(1-0.04)/100]
UCL = 0.04 + 3√[0.000224]
UCL = 0.04 + 3 x 0.01497
UCL = 0.04 + 0.04491
UCL = 0.08491
Rounding off to three decimal places, the upper control limit is
0.099, which is answer choice B.

A P Chart Is to Be Developed for Use in Quality