Hello all, I'm trying to do an analysis and am having trouble coming up with an equation/calculation that I feel confident addresses what I need...

Assuming in period one that [ A1 * B1 = C1 ].

during the second period, A1 and B1 have both changed (increased/decreased) to A2 and B2, respectively, so that now [ A2 * B2 = C2 ].

My problem is - how can I quantify how much of the change in C was attributable to each the change in A and the change in B? Said another way, what percentage (or amount) of the total change in C was driven solely by the change in A? (and the same for B)?

Does that make sense? I tried posting a similar question in a different forum a couple of weeks ago, but the answer didn't address exactly what i was looking for, probably due to my lack of clarity; hopefully it's more understandable this time...

Thanks in advance for any responses - any help would be greatly appreciated.

Lewis