I'm trying to compare three groups but the fact that two of theml only show values of zero is giving me a hard time. Specifically, I'm comparing the production of a metabolite (M3G) by three cell lines. the results are as follow :
Line 1 : mean = 0 SEM = 0, n=10
Line 2 mean = 0, SEM = 0, n=10
Line 3 : mean = 2.89, SEM = 0.23, n=10
Here are the values for cell line 3 :
> 3,52 4,37 2,51 2,71 2,48 2,09 2,73 2,92 2,80 2,66
All the values for cell lines 1 and 2 are 0.
What test should I use to compare these cell lines ? I've been trying to find an answer and came up with a thread recommending a one-sample t-test, but I have three groups... I'm not sure what to do as I'm no expert in statistics ! For my other analyses (comparing groups with means different from zero), I usually use Mann-Whitney : is this applicable here ?