Az Ha wrote:
I have a set of data where two groups of animals walk around in an environment and I have calculated the percentages of the area covered by them. Each group covers different area, for example the arithmetic mean is 35% and 23% with n=40 and 29 respectively. ... Should i use unpaired T-test or prop.test? ..
Distribution questions aside, you should also consider what your story is.
From the animal's viewpoint, a doubling from 1% to 2% is as good as one from
30% to 60%, so the proportion is the measure of success. If you are an ecologist, a change in population from 30% to 60% might be close to disaster for the environment, so percentage points (60-30) or (2-1) is the right choice. Dieter
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