Answer:
C = .40n
Explanation:
The line shows that the graph is proportional. I know this because the graph is linear and goes through the origin (0,0). This means that I can take any point and put it in the form y/x to find the slope.
I took the point (10,4) on the graph. I put that in the form y/x = 4/10. 4/10 = .40 which is my slope.
C= .40n