Explanation:
I assume we're naming the graph
Seeing the situation:
We have $4 for bonus bucks
We have $50 for amount spent
On the bottom we have the 50, so we can put "Amount spent" in that box
On the left, we have 4, so we can put "Bonus bucks" in that box
At the top, the name is your choice, but we can combine the names in a way... "Bonus Bucks per amount spent"... I guess that works
Looking at the graph, it's correct, but it's in reverse. you want your first dot where the 50 and 4 intersect, then you go diagonally upwards