Answer
$$\frac{1}{256}$$
Work Step by Step
We know the following rule: $$(\sqrt[n] x)=x^{\frac{1}{n}}$$
Using this as well as the rules of exponents learned in a past chapter (and listed on page 330, if review is necessary), we find:
$$(\sqrt[3] {64})^{-4} \\ 4^{-4} \\\frac{1}{256}$$
