If We Are Testing for the Difference Between the Means

question 138

Multiple Choice

If we are testing for the difference between the means of 2 independent populations presuming equal variances with samples of n₁ = 20 and n₂ = 20, the number of degrees of freedom is equal to

• A) 39.
• B) 38.
• C) 19.
• D) 18.

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Definitions:

Permafrost

Of arctic tundra, a perpetually frozen layer of soil that prevents water from draining.

Biome

A region (often discontinuous) characterized by its climate and dominant vegetation.

Rainfall

The amount of precipitation, in the form of liquid water drops, that falls to the ground from clouds.

Corals

Marine invertebrates in the class Anthozoa that often live in compact colonies; they are major contributors to the physical structure of coral reefs.