TABLE 18-3
a Quality Control Analyst for a Light Bulb

question 12

Multiple Choice

TABLE 18-3
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.
$$\begin{array} { l c c } \text { Day } & \bar { X } \text { (in minutes) } & R \\\hline 1 & 58.5 & 5.1 \\2 & 47.6 & 7.8 \\3 & 64.3 & 6.1 \\4 & 60.6 & 5.7 \\5 & 63.7 & 6.2 \\6 & 57.5 & 6.0 \\7 & 55.0 & 5.4 \\8 & 54.9 & 6.1 \\9 & 55.0 & 5.9 \\10 & 62.7 & 5.0 \\11 & 61.9 & 7.1 \\12 & 60.0 & 6.5 \\13 & 58.3 & 5.9 \\14 & 52.0 & 5.2\end{array}$$
-Referring to Table 18-3, suppose the sample mean and range data were based on 11 observations per day instead of 10. How would this change affect the lower and upper control limits of the R chart?

• A) LCL would remain the same; UCL would decrease.
• B) LCL would increase; UCL would decrease.
• C) Both LCL and UCL would remain the same.
• D) LCL would decrease; UCL would increase.

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Definitions:

Machine Shop

A workshop where various machines are used for cutting, shaping, and finishing metals or other materials to manufacture parts or products.

Grinding

A process involving repetitive tasks to achieve a certain level of status or accomplishment, commonly referenced in gaming and work contexts.

Drilling

Drilling is the process of creating holes in the earth's surface or other materials, often for exploration or extraction of natural resources.

Pressing

Urgent or demanding immediate attention or action, often due to critical importance or severity.