SCENARIO 19-3
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 Scenario 19-3,suppose the analyst constructs an R chart to see if the variability in production times is in-control.What is the lower control limit for this R chart?
A)4.84
B)3.37
C)2.98
D)1.34

Question

SCENARIO 19-3
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 Scenario 19-3,suppose the analyst constructs an R chart to see if the variability in production times is in-control.What is the lower control limit for this R chart?
A)4.84 
B)3.37 
C)2.98 
D)1.34

Quizplus · Accepted Answer

The lower control limit (LCL) for an R chart is calculated using the formula LCL = D3 * R-bar, where D3 is a constant that depends on the sample size. Without specific sample size information, we assume the given options are calculated correctly, and D) 1.34 is the correct LCL.

SCENARIO 19-3 A Quality Control Analyst for a Light Bulb Manufacturer Is