TABLE 14-3
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 14-3, suppose the analyst constructs an R chart to see if the variability in production times is in control. The R chart is characterized by which of the following?
A) increasing trend
B) decreasing trend
C) in control
D) points outside the control limits

Question

TABLE 14-3
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 14-3, suppose the analyst constructs an R chart to see if the variability in production times is in control. The R chart is characterized by which of the following?
A) increasing trend 
B) decreasing trend 
C) in control 
D) points outside the control limits

Quizplus · Accepted Answer

The R chart is in control as there are no points outside the control limits and no noticeable trend.

TABLE 14-3 A Quality Control Analyst for a Light Bulb Manufacturer Is