Basically compare with your value with the value of A both for some specific B (Let A' be the value you have and A be the value calculated from the regression).
If A' > A then its above, if A' < A then below.
I have competed the following regression analysis which has returned an equation of:
A = (0.2429 * B) + -0.2603
As I already know the values of A and B, is possible to rearrange the equation so that i can determine whether a value plots above or below the line. I.E. if value is positive plots above and vice versa?