Spearman correlation rank test

rs = 1 - {6S/(n3-n)}

Rank (from 1 to n, where n is the number of pairs of data) the numbers in each column. If there are ties within a column , then assign all the measurements that tie the same median rank.

Note, avoids ties (which reduce the power of the test) by measuring with as fine a scale as possible. S= sum of the square differences in rank. (ref)

X Y Rx Ry

1 8 1 4

6 2 3 1

6 3 3 2

n=4 6 4 3 3

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