Suppose you mow lawns to make some extra money. The amount of money you varies directly with the number of hours you work. If you mow 4 lawns and earn $48, what is the constant of variation?

I'm probably wrong but here goes

If you mow 4 lawns for $48 dollars you made $12 dollars a lawn. That probably means about $12 dollars per hour mowing and that's the constant (the money value) of variation (the different amount of hours you could choose to work)