We want to use an inverted cone with a radius of 9cm to dispense 100mL of a chemical. To be certain that we dispense the correct quantity we want markings in 100mL increments on the outside of the cone. Where should we place the markings?(accurate to .1 of a mm).

The volume of the inverted cone can be found with V=(32a^3)/27 where a is the radius of the cone

So far all I have done is sub in the radius to work out the volume

Any help would be greatly appreciated