#### Answer

$\frac{4}{7}$

#### Work Step by Step

According to the quotient product of radicals, $\sqrt[n] \frac{a}{b}=\frac{\sqrt[n] a}{\sqrt[n] b}$ (where $\sqrt[n] a$ and $\sqrt[n] b$ are real numbers and $n$ is a natural number). That is, the nth root of a quotient is the quotient of the nth roots.
Therefore, $\sqrt \frac{16}{49}=\frac{\sqrt 16}{\sqrt 49}=\frac{4}{7}$.
$\sqrt 16=4$, because $4^{2}=16$
$\sqrt 49=7$, because $7^{2}=49$