A Design Engineer Wants to Construct a Sample Mean Chart

question 75

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: $$\begin{array} { c c c c c } \text { Sample } && { \text { Service Life (hours) } } \\\hline 1 & 495 & 500 & 505 & 500 \\2 & 525 & 515 & 505 & 515 \\3 & 470 & 480 & 460 & 470\end{array}$$
What is the standard deviation of the sampling distribution of sample means for whenever service life is in control?

• A) 5 hours
• B) 6.67 hours
• C) 10 hours
• D) 11.55 hours
• E) 20 hours

---

Definitions:

Personal Space

The physical area surrounding an individual that is considered personal territory, which others are typically not expected to intrude upon without consent.

Divisiveness

The tendency or characteristic of causing disagreement, discord, or splitting groups into opposing factions.

Power Distance

A cultural dimension that describes the extent to which individuals in a society accept and expect power to be distributed unequally.

Sense of Individualism

A philosophy or social outlook that emphasizes the moral worth of the individual.