posted by Kimmy .
To be written on the axis of a graph,suggest two quantities that might be described by the statement.
1) When one quantity decreases, the other decreases.
2) When one quantity decreases, the other increases.
3) When one quatity increases, the other decreases.
4) Both quantities change independently of each other.
I can't answer that without seeing the graph. (2) and (3) seem to describe the same relationship. If (4) were true, you'd have a scatter plot, or a 3-D graph, or no graph at all.