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

question 125

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 is the center line of this R chart?

• A) 20.00
• B) 20.56
• C) 20.40
• D) 24.00

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Definitions:

Cohesive Groups

Social units where members share strong bonds, leading to high levels of cooperation and mutual support.

Incohesive Groups

Groups lacking unity or coherence, often resulting in lower effectiveness or productivity.

Norms

Shared expectations and rules that guide behavior of people within social groups.

Performance

Refers to the level at which an individual, group, or organization accomplishes its goals and objectives effectively and efficiently.