the answer:
the main formula for computing the multiplicative rate of change is given by:
Mutiplicative Rate of Change = [f(x2)/f(x1)] / (x2 -x1)
this formula can be written as
[f(x2)/f(x1)] / (x2 -x1) = [f(x2) * (x2 -x1) /f(x1)]
for example we can take (x1, f(x1))= (0, 2) and (x2, f(x2))= (1, 5)
therefore,
Mutiplicative Rate of Change = [5/2] / (1-0)= 5/2= 2.5
the answer is 2.5