Afarmer wishes to paint the side of a cylindrical grain silo of height 60 feet and diameter 24 feet. if the paint is to be applied in a coat 1/8 inch thick, use differentials to approximate the volume of paint that the farmer needs to buy.

i calculated that to be 15pi ft^3
it then asked for the actual error in approximation which i got to be 0.0205 ft^3

what is the relative error when compared to actual volume of paint required? (round your answer to six decimal places.)
this i don't know how to solve