Plug in numbers in for x. If you plug in 0 then you get 1. 1/0 is undefined If you plug in 1 then you get 6. 6/1 is 6 If you plug in 2 then you get 11. 11/2 is 5.5 If you plug in 3 then you get 16. 16/3 is 5.3 repeating If you plug in 4 then you get 21. 21/4 is 5.25 If you plug in 5 then you get 26. 26/5 is 5.2 It would only be proportional if you got the same answer after dividing each time.