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

question 114

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 $\bar { X }$ chart to see if the process is in-control. What is the center line of the chart?

• A) 20.00
• B) 20.26
• C) 21.00
• D) 24.26

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Definitions:

Return On Investment

A measure of the profitability of an investment, calculated by dividing the gain from the investment by the cost of the investment.

Combined Margin

A metric that combines multiple types of profit margins (such as gross, operating, or net margin) to assess overall performance.

Contribution Margin Ratio

The percentage of sales revenue remaining after variable costs are deducted, indicating how much contributes to fixed costs and profit.

Fixed Expenses

Costs that do not change with the level of production or sales over a certain period, such as rent, salaries, and insurance.