Question

What is the constant of proportionality for the graph? The graph is attached

Answer 1

The answer is A. 0.5. 

When you go out 1 on the X-axis you go up 0.5 on the Y-axis, thus the ratio is 0.5.

This is not easy to see, but if you go out 10 on the X-axis, it is easy to see that the Y-axis is at 5. Again giving the ratio 5/10=0.5