In order to achieve higher levels of customer satisfaction, a company begins monitoring the complaint resolution process of its customer service representatives. As a first step, the company decides to collect data on the number of unanswered calls out of the first 250 incoming calls to its call centre made each day. At the end of monitoring 25 days, it was found that a total of 500 incoming calls went unanswered. The control limits for the p chart of these data are
A) 0.029 and 0.131.
B) 0 and 0.304.
C) 0.066 and 0.094.
D) 0.048 and 0.112.
E) 0.102 and 0.112.

Question

Quizplus · Accepted Answer

The control limits for a p-chart are given by:UCL = p + 3√(p(1-p)/n)LCL = p - 3√(p(1-p)/n)where p is the proportion of nonconforming items, and n is the sample size.In this case, p = 500/2500 = 0.2, and n = 250.Therefore, the control limits are:UCL = 0.2 + 3√(0.2(1-0.2)/250) = 0.131LCL = 0.2 - 3√(0.2(1-0.2)/250) = 0.029

In Order to Achieve Higher Levels of Customer Satisfaction, a Company