TABLE 17-3
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 Table 17-3, suppose the analyst constructs an R chart to see if the variability in production times is in-control. What is the center line of this R chart?
A) 4.8
B) 6.0
C) 6.9
D) 7.1

Question

TABLE 17-3
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 Table 17-3, suppose the analyst constructs an R chart to see if the variability in production times is in-control. What is the center line of this R chart?
A) 4.8 
B) 6.0 
C) 6.9 
D) 7.1

Quizplus · Accepted Answer

The center line of an R chart is typically the average range of the samples. Without the specific data from Table 17-3, the choice that represents the average range is assumed to be 6.0.

TABLE 17-3 A Quality Control Analyst for a Light Bulb Manufacturer Is