TABLE 8-2 A Quality Control Engineer Is Interested in the Mean Length

question 45

Short Answer

TABLE 8-2
A quality control engineer is interested in the mean length of sheet insulation being cut automatically by machine. The desired mean length of the insulation is 12 feet. It is known that the standard deviation in the cutting length is 0.15 feet. A sample of 70 cut sheets yields a mean length of 12.14 feet. This sample will be used to obtain a 99% confidence interval for the mean length cut by machine.
-Referring to Table 8-2, suppose the engineer had decided to estimate the mean length to within 0.03 with 99% confidence. Then the sample size would be ________.

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Definitions:

Fixed Costs

Fixed costs are business expenses that remain constant regardless of the level of production or sales activities, such as rent, salaries, and insurance.

Contribution Margin

The sales price minus the variable costs of a product, indicating how much selling one more unit adds to profit.

Variable Costs

Costs that vary directly with the level of production or volume of output, such as raw materials and direct labor.

Fixed Costs

Costs that remain constant regardless of the volume of goods or services produced by a business.