Well take the two ratios and simplify down.
(10) (5)(2) (5)
----- = ------- = -----
(14) (7)(2) (7)
(30) (5)(6) (5)
----- = -------- = -----
(36) (6)(6) (6)
So we simplified both fractions down to:
(5) (5)
----- ------
(7) (6)
Since we know (5/7) and (5/6) are not equal, we know that they are not proportional.
