A Quality Analyst Wants to Construct a Sample Mean Chart

question 86

Multiple Choice

A quality analyst wants to construct a sample mean chart for controlling a packaging process. He knows from past experience that whenever this process is in control, package weight is normally distributed with a mean of 20 ounces and a standard deviation of two ounces. Each day last week, he randomly selected four packages and weighed each: $$\begin{array} { l l c c c } \text { Day } & &{ \text { Weight (ounces) } } \\\hline \text { Monday } & 23 & 22 & 23 & 24 \\\text { Tuesday } & 23 & 21 & 19 & 21 \\\text { Wednesday } & 20 & 19 & 20 & 21 \\\text { Thursday } & 18 & 19 & 20 & 19 \\\text { Friday } & 18 & 20 & 22 & 20\end{array}$$
If he uses upper and lower control limits of 22 and 18 ounces, what is his risk (alpha) of concluding this process is out of control when it is actually in control (Type I error) ?

• A) 0.0026
• B) 0.0456
• C) 0.3174
• D) 0.6826
• E) 0.9544

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Definitions:

Factory Overhead

The total of all costs that are incurred to manufacture products, excluding the direct costs of labor and materials.

Sales Supplies Used

Pertains to the total cost of sales or promotional materials consumed or utilized during a particular period.

Selling and Administrative Expense

Selling and administrative expense includes costs related to the selling of products and the management of the business, excluding production costs.

Factory Overhead

Costs tied to manufacturing processes, excluding those for direct labor and materials.