SCENARIO 18-4
a Factory Supervisor Is Concerned That the Time

question 148

Multiple Choice

SCENARIO 18-4
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 Scenario 18-4, suppose the supervisor constructs an R chart to see if the variability in collection times is in-control. What are the lower and upper control limits for this R chart?

• A) - 2.33, 43.13
• B) - 2.28, 42.28
• C) 0, 42.28
• D) 0, 43.13

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Definitions:

Pie Charts

Graphical representations of data in a circular format, with slices to illustrate proportional sizes of different categories within a whole.

Labeling

The act of assigning a name, category, or description to individuals, groups, or objects, which can influence perceptions and behaviors.

Legend

A set of symbols or explanatory notes appearing on a map or document.

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