The table of values and their graph show above a straight line that passes through the origin. This indicates that the relationship between the two currencies is in direct proportion. Think about what this means in real terms – if you have ten times more dollars than another person, when you both exchange your money, you will still have ten times more money. Notice also that the graph passes through the origin; this makes sense as if you have no dollars you will get no pounds!
We can express these relationships algebraically as well as graphically.
