If the relationship between distance y in feet and x in seconds is proportional, which rate is represented by x/y=0.6?

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.