Instruction 18-9
A quality control analyst for a light bulb manufacturer is concerned that the time it takes to produce a batch of light bulbs is too erratic.Accordingly,the analyst randomly surveys 10 production periods each day for 14 days and records the sample mean and range for each day.
-Referring to Instruction 18-9,suppose the analyst constructs an R chart to see if the variability in production times is in control.The R chart is characterised by which of the following?
A)Increasing trend.
B)In control.
C)Decreasing trend.
D)Points outside the control limits.

Question

Quizplus · Accepted Answer

An R chart is used to monitor the variability in a process. The chart includes upper and lower control limits based on the expected range of the process. If the process is in control, the points on the R chart should fall within the control limits and show no distinct pattern or trend. An increasing or decreasing trend would indicate that the process is not stable over time. Points outside the control limits would indicate that the process is out of control and may need to be investigated for causes of variation. Therefore, the correct answer is B, in control.

Instruction 18-9 A Quality Control Analyst for a Light Bulb Manufacturer Is