Molar Extinction Coefficient Trouble!

[sophi3nutt]

I have a graph of absorbance against concentrations of BCG dye at 614 nm.
I have been asked to estimate the molar extinction coefficient for BCG from the graph and show how my value was calculated. The Molecular weight values for BCG is 698.

I simply do not know where to start!
So far:
E=A/c
I have an absorbance of 0.406/0.35 = 1.16 L.mol-1.cm-1...but do not know what to do regarding the molecular weight.

[alexandertg6]

nothing. ignore it. A=EbC where E is molar extinction coefficient, b is the path of light in cm, and C is concentration