The average time (minutes) that a customer has to wait for the arrival of a cab after

Question:

The average time (minutes) that a customer has to wait for the arrival of a cab after calling the company has been observed for random samples of size 4. The data for 20 such samples are shown in Table 7-28. Previous analysis gave the upper and lower control limits for an X-chart when the process was in control as 10.5 and 7.7 minutes, respectively. What is your estimate of the standard deviation of the waiting time for a customer? Construct a moving-average control chart using a span of 3. What conclusions can you draw from the chart?image text in transcribed

Step by Step Answer:

Related Book For  book-img-for-question
Question Posted: