Is y=3/4x proportional or non proportional

The volume of a cube is 8 in to the 3rd power. how long is each side?

Miss henderson wants to build a fence around a rectangular garden in her backyard in the scale drawing the perimeter of the garden is 14 in of the actual length of a b is 20 ft how many feet of fencing what you need

Yvaries directly as x. y =90 when x=6. find y when x=13