Step-by-step explanation:
f(x + 1) = (5/2)*f(x)
f(x + 1) = 2.5*f(x), f(1) = 3.2
f(2) = 2.5f(1) = 2.5*3.2 = 8
f(3) = 2.5f(2) = 2.5*8 = 20
f(4) = 2.5f(3) = 2.5*20 = 50
f(5) = 2.5f(4) = 2.5*50 = 125