the volume of a box varies directly with its length. if the box has a volume of 90 cubic inches and a length of 15 inches, what is the constant of proportionality for the box?

Respuesta :

The direct variation formula is y = kx, with k being the constant of variation. Here, volume is our y and length is our x: 90 = k(15) and k = 90/15 so k = 6