I have 2 samples, A and B. I subjected both samples to extraction and got the amount of yield (the dependent variable).
I just want to see if there is a significant difference between the yield for A and B.
Each sample had 3 replicates.
4.832, 4.828, 4.662
Since it's just 2 samples, I went for a two-sample t-test.
I tested for normality, which indicated the data was not normal.
I did a log transform, but it was still not normal.
Anyway I subject the log yield to the t-test and got equal variance and p value 0.00
And I tried non-parametric test (Mann-Whitney) and got p-value 0.046.
I don't get why is the p-value of Mann-Whitney so close to 0.05. Can it be that the means of sample A and B do not differ significantly when the values seem so far apart?
What am I doing wrong?