Discuss the below:
Q: Acme believes that the majority of the incorrect invoices come from within the accounts receivable department. You are the manager of the accounts receivable department and you want to confirm or deny the company's assertion.
You decide to monitor the activities of your department very closely for one month.
You conduct a sampling technique drawing on 200 clients' invoices over a 30-day period and check the accuracy of each invoice. The sample results are as follows:
DAY ERROR
1 10
2 14
3 11
4 15
5 16
6 12
7 14
8 13
9 9
10 10
11 9
12 14
13 14
14 3
15 15
16 8
17 2
18 8
19 6
20 2
21 2
22 10
23 15
24 5
25 6
26 6
27 5
28 7
29 3
30 13
Develop a p-chart for the data above using 3σ control limits.
Explain whether the department is at fault or not.