In Testing the Difference Between the Means of Two Normally

question 16

Multiple Choice

In testing the difference between the means of two normally distributed populations,if μ₁ = μ₂ = 50,n₁ = 9,n₂ = 13,the degrees of freedom for the t statistic equals ___________.

• A)22
• B)21
• C)19
• D)20

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Definitions:

Acid Rain

Precipitation containing harmful amounts of sulfuric and nitric acids resulting from the atmospheric emission of sulfur dioxide and nitrogen oxides.

Scrubbers

Pollution control devices designed to remove particulates and/or gases from industrial exhaust streams.

Primary Standard

A main or leading benchmark that sets the necessary specifications or criteria for processes, products, or services.

Air Pollution

The presence of harmful or excessive quantities of substances in the air that pose risks to human health and the environment.