Direct Variation. (Y = KX). Direct Variation Method “Y” varies directly as “X” means y = kx Y is a unit and X is another unit. Example: If weight varies directly as height and a person who is 73 inches tall weighs 210 lbs. then how tall is a person who weighs 180 lbs.?
(Y = KX)
If the volume of a polyhedron varies directly as the square root
of its surface area, when the volume is 60 cu. ft. with a
surface area 100 sq. ft. what’s the volume for a polyhedron with
a surface area of 400 sq. ft.?