Answer
$$\frac{y^{\frac{5}{2}}}{x^{\frac{9}{4}}}$$
Work Step by Step
Using the rules of exponents, we find:
$$ \frac{x^{\frac{1}{4}}y^3}{x^{\frac{5}{2}}y^{\frac{1}{2}}} \\ \frac{y^3}{x^{\frac{9}{4}}y^{\frac{1}{2}}} \\ \frac{y^{\frac{5}{2}}}{x^{\frac{9}{4}}}$$