$$f(x) = 10^{-3} * (1/3x³ - 6x²)$$
$$f(6) =10^{-3} * (1/3*6³ - 6*6²)$$= - 0,144→100%
$$f(4,5) =$$$$ 10^{-3} * (1/3*4,5³ - 6*4,5²)$$= - 0,091125→63,28%
$$f(3) = 10^{-3} * (1/3*3³ - 6*3²)$$ = - 0,045→31,25%
$$f(1,5) = $$$$10^{-3} * (1/3*1,5³ - 6*1,5²)$$= - 0,012375→8,59%