For upper and lower control limits of .026 and .014, which machine(s), if any, appear(s) to be out-of-control for process proportion of defectives?
A)machine #3
B)machine #4
C)machines #3 and #4
D)machines #2 and #3
E)none of the machines

Question

Quizplus · Accepted Answer

To determine if a machine is out-of-control for process proportion of defectives, we need to look at the control chart and check if any data points fall outside of the upper or lower control limits. 
- Machine #1 has all data points within the control limits, so it is in control. 
- Machine #2 has one data point above the upper control limit, so it is out-of-control. 
- Machine #3 has two data points above the upper control limit and one below the lower control limit, so it is out-of-control. 
- Machine #4 has one data point below the lower control limit, so it is out-of-control.

Therefore, machines #3 and #4 are out-of-control and appear to have issues with their process proportion of defectives.

For Upper and Lower Control Limits of