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

question 42

Multiple Choice

TABLE 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.
$$\begin{array} { l l l l } \text { Hour } & \bar { X } & \text { R } \\\hline 1 & 18.4 & 25 \\2 & 16.9 & 27 & \\3 & 23.0 & 30 & \\4 & 21.2 & 23 & \\5 & 21.0 & 24 & \\6 & 24.0 & 25 & \\7 & 19.3 & 12 \\8 & 15.8 & 14 & \\9 & 20.0 & 13 & \\10 & 23.0 & 11 &\end{array}$$ 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 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) 24.00
• B) 20.00
• C) 20.56
• D) 20.40

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Definitions:

Hair Dryers

Electrical devices used to dry and style hair by blowing hot air over it.

Quantity Supplied

The amount of a certain good or service that producers are willing and able to sell at a given price during a specific time period.

Manufacturing Workers

Individuals employed in sectors that involve physical production and assembly of goods, including machinery, textiles, and electronics.

The General Theory

Refers to John Maynard Keynes' "The General Theory of Employment, Interest, and Money," a foundational text in the study of macroeconomics.