If for example, on an exam, a teacher were to give students a Beer's law plot (graph), with absorbance on the y axis, and concentration in ppm on the x axis. The teacher gives the equation of the graph in the form y = mx + b, or y = .800x, for example. If the teacher asked for the absorbance, and gave the ppm value or the y-axis values, you would simply plug the values into the equation, and solve for y or x depending on what value he gave you, and that would be absorbance correct? If he asked for transmittance, then that would 10^-abs (ten to the negative absorbance). Please correct me if I am wrong.