The Mean Gross Annual Incomes of Certified Welders Are Normally $\pm$

question 85

Multiple Choice

The mean gross annual incomes of certified welders are normally distributed with the mean of $20,000 and a standard deviation of $2,000.The ship building association wishes to find out whether their welders earn more or less than $20,000 annually.The alternate hypothesis is that the mean is not $20,000.If the level of significance is 0.10,what is the critical value?

• A)1.65
• B)2.58
• C)1.28
• D)\(\pm\)1.28
• E)\(\pm\)1.65

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Definitions:

Density

A physical property defined as the mass of a substance per unit volume, usually expressed in grams per cubic centimeter or kilograms per cubic meter.

Density

The mass per unit volume of a substance, indicating how much matter is packed into a particular space.

Volume

A measurement of the three-dimensional space occupied by an object or a substance.