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 upper control limit for this R chart?
A)10.66
B)9.37
C)7.98
D)6.34

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 upper control limit for this R chart?
A)10.66 
B)9.37 
C)7.98 
D)6.34

Quizplus · Accepted Answer

The upper control limit (UCL) for an R chart is calculated using the formula UCL = D4 * R-bar, where D4 is a constant that depends on the sample size and R-bar is the average range of the samples. Without the specific values of D4 and R-bar provided in the scenario, we can't calculate the exact UCL. However, given the options, 10.66 is a plausible value for an upper control limit on an R chart, indicating it's a standard answer format for such questions.

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