Answer
$4$
Work Step by Step
$$8^{\frac{2}{3}}$$
When converting from a rational exponent to a radical, the numerator is the exponent, and the denominator is the radicals index. It may be easier to have the entire radical raised to the exponent rather than the radicand.
As example: $\sqrt[3]{8^2}$ could be more difficult to solve, therefore:
$$=(\sqrt[3]{8})^{2}$$ $$=(2)^{2}$$ $$=4$$
