Asked by Keondre Argyle on May 06, 2024
Verified
A bank's manager has videotaped 20 different teller transactions to observe the number of mistakes being made. Ten transactions had no mistakes, five had one mistake and five had two mistakes. Compute proper control limits at the 90% confidence level.
Confidence Level
A statistical measure expressed as a percentage, indicating the degree of certainty that a parameter lies within a specified range in a confidence interval.
- Compute and analyze process capability indices and control limits across various types of control charts such as X-bar, R-chart, p-chart, and c-chart.
- Examine sample data to ascertain whether a process is under statistical control.
- Implement the three-sigma guidelines to ascertain process control.
Verified Answer
LR
Leandra RubillosMay 11, 2024
Final Answer :
A c-chart should be used, and from Table S6.2 in the text, the z-value = 1.65.
The mean c-bar = [10(0) + 5(1) + 5(2)]/20 = 0.75.
UCLC = 0.75 + 1.65
0.75\sqrt { 0.75 }0.75 = 2.18
LCLC = 0.75 - 1.65
0.75\sqrt { 0.75 }0.75 = -0.68 (or 0)
The mean c-bar = [10(0) + 5(1) + 5(2)]/20 = 0.75.
UCLC = 0.75 + 1.65
0.75\sqrt { 0.75 }0.75 = 2.18
LCLC = 0.75 - 1.65
0.75\sqrt { 0.75 }0.75 = -0.68 (or 0)
Learning Objectives
- Compute and analyze process capability indices and control limits across various types of control charts such as X-bar, R-chart, p-chart, and c-chart.
- Examine sample data to ascertain whether a process is under statistical control.
- Implement the three-sigma guidelines to ascertain process control.