A Design Engineer Wants to Construct a Sample Mean Chart

question 59

Multiple Choice

A design engineer wants to construct a sample mean chart for controlling the service life of a halogen headlamp his company produces. He knows from numerous previous samples that this service life is normally distributed with a mean of 500 hours and a standard deviation of 20 hours. On three recent production batches, he tested service life on random samples of four headlamps, with these results: $$\begin{array} { c c c c c } \text { Sample } && { \text { Service Life (hours) } } \\\hline 1 & 495 & 500 & 505 & 500 \\2 & 525 & 515 & 505 & 515 \\3 & 470 & 480 & 460 & 470\end{array}$$
If he uses upper and lower control limits of 520 and 480 hours, on what sample(s) (if any) does service life appear to be out of control?

• A) sample 1
• B) sample 2
• C) sample 3
• D) both samples 2 and 3
• E) all samples are in control

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Definitions:

Language Development

The process by which children acquire the ability to perceive, comprehend, and produce language, including both spoken and written forms.

Chomsky

An American linguist, philosopher, cognitive scientist, and historian who revolutionized the study of linguistics with his theory of generative grammar.

Thinking and Language

The cognitive processes involved in formulating ideas, solving problems, and the use of language to communicate thoughts.

Language Determines

Likely refers to the linguistic relativity hypothesis, which suggests that the structure and vocabulary of one's language influence and shape one's thoughts and perceptions of the world.