Many Textbooks (Though Not This One) Advocate Testing the Mean

question 45

Multiple Choice

Many textbooks (though not this one) advocate testing the mean of a sample against a hypothesized population mean by using z even if the population standard deviation is not known, so long as the sample size exceeds 30. Those books recommend this because

• A) they don't know any better.
• B) there are not tables for t for more than 30 degrees of freedom.
• C) the difference between t and z is small for that many cases.
• D) t and z are exactly the same for that many cases.

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Definitions:

Variance Standard

A method used in budgeting and accounting to analyze the difference between planned financial outcomes and actual results.

Quantity Standard

A predetermined benchmark of the amount of input that should be used in the production of goods or services.

Quantity Variance

The difference between the actual quantity of material used in production and the standard quantity expected to be used.

Direct Materials

Raw materials that can be directly associated with the production of a product and are an integral part of the finished product.