You'll want to start by labeling the points at (1,2.3) and at (6,6.8) which is the first pairs that you are given. You'll want to find use the formula to find the rise and the run which I'll give
(6.8-2.3)/(6-1) which is 4.5/5 which is 0.9
So for each week you'll make a total of 0.9 million dollars.
