Mann-Whitney U Test Calculator
Raw Data (4 values each)
From U-Statistic
Formula
U = R - n(n+1)/2, z = (U - n1*n2/2) / sqrt(n1*n2*(n1+n2+1)/12)
Frequently Asked Questions
What is the Mann-Whitney U test?
The Mann-Whitney U test is a non-parametric test that compares two independent groups without assuming normal distributions. It tests whether one group tends to have larger values than the other by ranking all observations.
When should I use Mann-Whitney instead of a t-test?
Use the Mann-Whitney U test when your data violates the normality assumption, when dealing with ordinal data, or when sample sizes are very small. It is more robust to outliers.
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