The formula for the surface area of a sphere is 4πr^2
This can be used in the following way, getting the diameter at 18.3:
18.3/2 = 9.15
Saying PI is 3.14 you can do this:
SA = 4*3.14*9.15^2 = 1051.6 m^2
Formula for volume is:
(4/3)πr^3
V = (4/3)*3.14*9.15^3 = 3207.2 m^3