Hi All, quick question on non-parametric t-test
I have 2 groups. 7 values each.
Group One= 0, 0, 0, 0, 0, 0, 0 which of course is mean=0 and SEM=0
Group Two= 0, 0, 21, 35, 0, 0, 0 mean=8 and SEM=5.4
When I do unpaired non-parametric Mann-Whitney two-tail test, I am told that because...