If y varies directy as x, and y is 20 when x is 4, what is the constant variation for this relation

Match each three-dimensional figure to its volume based on the given dimensions. (assume π = 3.14.) a right cylinder with radius 4 cm and height 3 cm 314 cu cm a cone with radius 5 cm and height 12 cm 160 cu cm a pyramid with base area 16 sq cm and height 30 cm 48 cu cm a pyramid with a square base of length 3 cm and height 16 cm 150.72 cu cm