Answer
$\color{blue}{\frac{1}{n}\sqrt[4]{m}}$
Work Step by Step
Factor the radicand so that one factor is a perfect fourth power to obtain:
$=\sqrt[4]{\left(\frac{1}{n^4}\right)(m)}
\\=\sqrt[4]{\left(\frac{1}{n}\right)^4(m)}$
Bring out the cube root of the perfect cube factor to obtain:
$\\=\color{blue}{\frac{1}{n}\sqrt[4]{m}}$