Below is Mann-Whitney test result from Minitab. At the end of result, there is no p-value but "
Cannot reject since W is < 363.0". What does it mean? I cannot reject H0? But the median looks significantly different here.
======================================================================== Mann-Whitney Test and CI: 20_C_or_Better_Grade_2013, 2124_C_or_Better_Grade_201 N Median 20_C_or_Better_Grade_2013 22 5.500 2124_C_or_Better_Grade_2013 10 10.500 Point estimate for ETA1-ETA2 is -5.000 95.1 Percent CI for ETA1-ETA2 is (-9.000,-0.001) W = 315.5 Test of ETA1 = ETA2 vs ETA1 > ETA2 Cannot reject since W is < 363.0