EXPLANATION :
f(x) has values of 1/6, 1/4, 3/8, 9/16, 27/32
As you notice, the next term is 3/2 of the previous term :
1/6 x 3/2 = 1/4
1/4 x 3/2 = 3/8
3/8 x 3/2 = 9/16
9/16 x 3/2 = 27/32
So we can say that the function's value changes by a factor of 3/2.
Then f(x) demonstrates that exponent functions change by equal ratios over equal intervals.