determine the volume of the cylinder with a diameter of 12 inches and a hight of 18 inches round to the nearest tenth

The answer is given by

pi * (d/2)^2 * h =

pi * (12/2)^2 * 18 =

pi * (6)^2 * 18   =  

pi * 36 * 18   =     ....   and you should be able to take it from there.....