Final answer:
The relationship between x and y is given by the equation y^2 = (1/16)x^3, which is derived from the given values x = 4 and y = 2.
Step-by-step explanation:
The question states that the square of y varies directly as the cube of x. This means we can write the equation as y^2 = kx^3, where k is the constant of variation. To find k, we use the given values of x = 4 and y = 2. Substituting these values into the equation, we get 2^2 = k(4^3), which simplifies to 4 = 64k. Therefore, k is 1/16. The equation representing the relationship is y^2 = (1/16)x^3.