1. The problem statement, all variables and given/known data I'ts part of a bigger problem, but this is all the info given. http://img238.imageshack.us/img238/7923/chartro3.jpg 2. Relevant equations I'm doing an experimental error calculation, and that equation wouldn't relevant, but that's the only one I got. 3. The attempt at a solution I wanted to slowly minus them together, but it would take really long since there are 12 points, there must be a shorter way, and the margin given for it (it is generally expected to fit) is too small to contain that much work.