Commonwealth Bank is trying to determine if their billing process for their cred

Question

Commonwealth Bank is trying to determine if their billing process for their credit card program is out of control. They have taken a daily sample of 100 customer bills for the past 10 days and checked them for accuracy. The number of bills that have errors out of each sample of 100 customer bills is as follows (i.e. either a bill contains one or more errors or it Sample Number of Bills with Errors 8 12 2 6 4 4 6 7 8 10 10 14 10 10 The type of control chart that should be used to monitor this process is an: O X-bar chart O p-chart O c-chart R-chart

Explanation / Answer

1) P chart should be used 2) Sample No. of Bills with Errors proportion 1 8 0.08 2 12 0.12 3 8 0.08 4 6 0.06 5 4 0.04 6 8 0.08 7 10 0.10 8 10 0.10 9 14 0.14 10 10 0.10 Total 90 P bar 0.09 UCL = p bar + 3*sqrt(pbar*(1-pbar)/100) 0.17585453 LCL = p bar - 3*sqrt(pbar*(1-pbar)/100) 0.00414547 Since next bill proportion is 15/100 0.15 which is less than UCL, so process is in control

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.