Question 18363
You can write proportions as an equation if you use an arbitrary constant of proportionality (k).

{{{x^2 = ky^3}}} Take the square root of both sides.
{{{(x^2)^(1/2) = k(y^3)^(1/2)}}} Simplify; Multiply the exponents.
{{{x = k(y^(3/2))}}}
Therefore:
{{{x}}} is proportional to {{{y^(3/2)}}}