Correct. Rewrite the expression as a radical. The denominator of the fraction determines the root of the radical.

$\displaystyle{{\left({64}{{a}}^{{3}}\right)}}^{{\frac{{1}}{{3}}}}={\sqrt[{{3}}]{{{64}{{a}}^{{3}}}}}\usepackage{cmbright}\Huge\$

Find the cube root of both the coefficient and the variable factor.

$\displaystyle{\sqrt[{{3}}]{{{{4}}^{{3}}\cdot{{a}}^{{3}}}}}={\sqrt[{{3}}]{{{{4}}^{{3}}}}}\cdot{\sqrt[{{3}}]{{{{a}}^{{3}}}}}={4}{a}\usepackage{cmbright}\Huge\$