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)

So what is the question