\[\sqrt[5]{8} = \sqrt[5]{2^{3}} = 2^{\frac{3}{5}};\ \ 2^{\frac{2}{3}};\]
\[\frac{3}{5} = \frac{9}{15};\ \frac{2}{3} = \frac{10}{15};\]
\[\sqrt[5]{8} < 2^{\frac{2}{3}}.\]