what test do i use to check for similarity between two groups using the x-axis which variable is independent of the x axis and y-axis? how to test if two populations are similar how to find the similarity of two population groups using the y-axis? how to test if two populations are similar over time y axis is independent of what variable why do people look at each other differently what is a statistical test to see if two populations are similar over time? how do you test when a two sample groups are comparable? when to use the y axis for testing differences how to find the similarities between two groups on the x axis when are the populations on the x-axis similar how do you tell if two populations are different do you use the x axis to measure the similarity between a population or a time variable which axis is used to measure correlation do two populations have a difference in time how to find if two populations are statistically different how to tell if two populations are similar what x axis test for comparing two populations which y axis does the correlation of a class a and class b test