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

question 10

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.

$\begin{array} { l c c } \text {Hour}&\bar { X } & R \\ \hline1 & 18.4 & 25 \\ 2 & 16.9 & 27 \\ 3 & 23.0 & 30 \\ 4 & 21.2 & 23 \\ 5 & 21.0 & 24 \\ 6 & 24.0 & 25 \\ 7 & 19.3 & 12 \\ 8 & 15.8 & 14 \\ 9 & 20.0 & 13 \\ 10 & 23.0 & 11 \end{array}$
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 X chart to see if the process is in-control. What are the lower and upper control limits of this chart?

• A) 8.49, 32.03
• B) 10.00, 30.00
• C) 5.39, 35.13
• D) 4.96, 35.56

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Definitions:

Demand Function

A mathematical representation of the relationship between the quantity demanded of a good and its influencing factors, like price.

Cobb-Douglas

A type of production function used in economics to represent the relationship of an output to inputs, specifically capital and labor, with constants denoting the output elasticity of each input.

Perfect Substitutes

Two or more goods that can be used in place of one another with no loss of utility for the consumer, resulting in constant marginal rates of substitution.

Perfect Substitutes

Goods or services that can be used in exactly the same way and are interchangeable by consumers.