I think im in a real pickle.
One of the section in the coursework talks about using a statistical test.
Now Ive looked at the T Test, Chi Squared and Man Whitney U but unless im mistaken they are all used for only two groups (dependant [CO2 production and independant[substrate]).
Is there any statistical test which includes all of the groups, or am I thinking about this in the wrong way?
Any help is GREATLY appreciated.

