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

question 9

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 $\bar{ X}$ chart to see if the process is in-control. Which expression best describes this chart?

• A) cycles
• B) decreasing trend
• C) hugging the center line
• D) increasing trend

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Definitions:

Fixed Mindset

The belief that abilities and intelligence are static and unchangeable traits.

Self-concept

An individual's perception of their own strengths, weaknesses, and unique qualities; a reflection of one's identity.

Physical

Pertaining to the body and its physiological functions, as opposed to the mind or emotional state.

Achievement Motivation

The willingness to persist at challenging tasks and meet high standards of accomplishment.