The circumference of the base of the cone is 8.5 inches. What is the volume of the cone in term of pi? Round to the nearest hundredth

========================================================
Work Shown:
C = 2*pi*r ......... circumference of the circular base
r = C/(2pi)
r = (8.5)/(2pi)
r = 4.25/pi
-------------
V = pi*r^2*h ...... volume of the cone
V = pi*(4.25/pi)^2*15
V = pi*(18.0625/pi^2)*15
V = (18.0625*15)/pi
V = 270.9375/pi ..... exact volume in terms of pi
If we round that decimal number up top to the nearest hundredth, then we end up with V = 270.94/pi