The diameter of a cone is x cm the height is 18 cm mthe the height is 18 cm and the volume is 301.44 cm what is x

The volume of a cone is V=(1/3)(area of the base)(height)= (1/3)(pi*r^2)(h)
r^2= (d/2)^2 = (d^2)/4. Given: V= 301.44cm^3 and h= 18cm.
r^2= V/[(1/3)(pi)(h)]
r^2= 3V/(pi)(h)
(d^2)/4= 3(301.44)/(3.14)(18)
d^2= 12(301.44)/(3.14)(18)
d^2= 63.967
d= 7.997
d~= 8cm.

Ithink it is 7. 16