I want to compare the proportions of 2 groups statistically. My data look like this (the actual dataset contains 700,000 rows):
GROUP A GROUP B GROUP C 0.7 0.2 0.1 0.3 0.4 0.3 0.2 0.23 0.57 … … …
So every row sums to 1. Moreover, the data are paired in the sense that every row is a proportion for the same subject.
Now I want to know whether the average proportion of GROUP A is significantly higher than the average proportion of GROUP B. Does anybody have an idea about the appropriate test for this? I could not find a specific test for this problem so far on the internet. I assume that a regular t-test is not appropriate in this case because I'm working with proportions.