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

question 8

Multiple Choice

SCENARIO 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. $\begin{array}{ccc} \underline{\text { Day } }& \underline{\bar{X} \text { (in minutes) }} & \underline{\text {R}}\\1 & 58.5 & 5.1 \\2 & 47.6 & 7.8 \\3 & 64.3 & 6.1 \\4 & 60.6 & 5.7 \\5 & 63.7 & 6.2 \\6 & 57.5 & 6.0 \\7 & 55.0 & 5.4 \\8 & 54.9 & 6.1 \\9 & 55.0 & 5.9 \\10 & 62.7 & 5.0 \\11 & 61.9 & 7.1 \\12 & 60.0 & 6.5 \\13 & 58.3 & 5.9 \\14 & 52.0 & 5.2\end{array}$

-Referring to Scenario 18-3, 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

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Definitions:

Restlessness

A condition of being unable to relax or remain still, often due to anxiety, discomfort, or other underlying health issues.

Cool Skin

A condition where the skin's temperature feels lower than normal, possibly indicating poor circulation or shock.

Uncontrolled Shivering

Involuntary and violent shaking of the body that cannot be stopped at will, often due to cold, fever, or other medical conditions.

Parenteral Nutrition

A technique which involves supplying nutrients directly into the bloodstream via an intravenous solution, avoiding the gastrointestinal tract altogether.