TABLE 17-4
a Factory Supervisor Is Concerned That the Time

question 64

Multiple Choice

TABLE 17-4
A factory supervisor is concerned that the time it takes workers to complete an important production task (measured in seconds) is too erratic and adversely affects expected profits. The supervisor proceeds by randomly sampling 5 individuals per hour for a period of 10 hours. The sample mean and range for each hour are listed below.
$\begin{array}{ccc} \underline { \text {Hour } }& \underline { \bar { X } } & \underline { R }\\1 & 18.4 & 25 \\2 & 16.9 & 27 \\3 & 23.0 & 30 \\4 & 21.2 & 23 \\5 & 21.0 & 24 \\6 & 24.0 & 25 \\7 & 19.3 & 12 \\8 & 15.8 & 14 \\9 & 20.0 & 13 \\10 & 23.0 & 11\end{array}$

She also decides that lower and upper specification limit for the critical-to-quality variable should be 10 and 30 seconds, respectively.
-Referring to Table 17-4, suppose the supervisor constructs an $\bar { X }$ chart to see if the process is in-control. Which expression best describes this chart?

• A) Decreasing trend
• B) In-control
• C) Increasing trend
• D) Individual outliers

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Definitions:

Thyroid Gland

A butterfly-shaped gland in the neck that produces hormones regulating metabolism and energy.

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A test to measure the body's response to glucose, assessing how quickly it is cleared from the blood, used in diagnosing diabetes.

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The concentration of glucose present in the blood, an important energy source for the body's cells and an indicator of metabolic health.

Glucose

An essential energy-supplying simple sugar present in living entities and a constituent of various carbs.