Suppose z varies directly with y and directly with the cube of x . If z = 1792 when x = 4 and y = 7 , what is z when x = 11 and y = 3 ?

Answer 1

z= kyx^3

1792 = k(7)(4) = 28k

k = 1792/28 = 448/7 = 64

z = 64yx^3

z = 64(3)(11)^3 = 192(121)11 = 192(1331)

z= 255,552