Question

You are working in a small, student-run company that sends out merchandise with university branding to alumni around the world. Every day, you take a sample of 50 shipments that are ready to be shipped to the alumni and inspect them for correctness. Across all days, the average percentage of incorrect shipments is 5 percent. What would be the upper control limit for a p-chart

Answer 1

Answer:

The answer is "0.142466".

Step-by-step explanation:

Using the p formula for the proportion of nonconforming units through the subgrouping which can vary in sizes:

$p =\frac{np}{n}$

$\bar{p}=\frac{\Sigma np}{\Sigma n}$

Defects $= \frac{5}{100} \times 50$

$p = \frac{5}{100} \times \frac{50}{50}=0.05$

It calculates the controls limits through the p-chart that is:

$UCL_{p},LCL_{p}=\bar{p} \pm \sqrt{\frac{\bar{p}(1-\bar{p})}{\bar{n}}}$

So, the upper control limits:

$= 0.05 + 3 \times \sqrt{(\frac{0.05\times(1-0.05)}{50})} \\\\= 0.142466$