The volume of a spherical hot air balloon V(r) =(4/3)(pi)(r^3)

Question

The volume of a spherical hot air balloon V(r) =(4/3)(pi)(r^3). The radius is a function of time given by r(t) = 3t.

 Find the average rate of change of the volume with respect to t as t changes from t = 1

 to t = 4.

Answer 1