Replace x with 1 nd solve, then replace x with 3 and solve:
x^3 - 2x^2 +3x
When x = 1: 1^3 -2(1)^2 +3(1) = 3 -3 +3 = 3
When x = 3: 3^3 -2(3)^2 + 3(3) = 27 -18 +9 = 18
The difference between the two solutions is 18-3 = 15
The difference between the two x values = 3-1 = 2
The rate of change is 15/2 or 7.5 as a decimal.