Answer
$4^{\frac{11}{15}}$
Work Step by Step
We can use the product rule to simplify, which holds that $a^{m}\times a^{n}=a^{m+n}$ (where a is a real number, and m and n are positive integers).
$4^{\frac{1}{3}}\times4^{\frac{2}{5}}=4^{\frac{1}{3}+\frac{2}{5}}=4^{\frac{5}{15}+\frac{6}{15}}=4^{\frac{11}{15}}$
