Answer:
39
Explanation:
Find the value of f(x) at both points
f(3) = 3(3)³ + 1 = 82
f(1) = 3(1)³ + 1 = 4
---------------------------
Average Rate of Change is just like slope
Divide the change in f(x) by the change in x
r = (82 - 4) / (3 - 1)
r = 78/2
r = 39