If the relationship is proportional, then we know that
('y' feet) = (rate) times ('x' seconds) .
Divide each side by 'x' : y ft / x sec = rate
Take the reciprocal of each side: x sec / y ft = 1/(rate)
You said that x sec / y ft = 0.6 .
So 1/rate = 0.6 sec / ft .
Rate = (1 and 2/3) ft/sec.
