#### Answer

$(19xy)^{\frac{3}{2}}$

#### Work Step by Step

RECALL:
$(\sqrt[n]{a})^m=\left(a^{\frac{1}{n}}\right)^m=a^{\frac{m}{n}}$
For the given expression, $n=2$, $a=19xy$, and $m=3$.
Thus, using the rule above gives:
$\left(\sqrt{19xy}\right)^3=\left((19xy)^{\frac{1}{2}}\right)^3=(19xy)^{\frac{3}{2}}$