I'm almost a bit ashamed to ask, but for some reason I'm stuck. Being a bit thick today I guess. Given is an empirical relationship A = 1.27*B^0.45 A = given. Say 2.5 What is B? For some reason, if I take a random but plausible B and calculate A, I get a different result then when I take the resultant A and try to result at the B I just made up. Either I can't rearrange equations anymore, or this relationship only works in one direction. Sounds silly... Help, please?