Answer
$\frac{11}{4}$
Work Step by Step
According to the textbook, a number, $a$, is a square root of another number, $b$, if $a^2=b$. When working with fractions, we want to find the square root of the both the numerator and the denominator.
$(\frac{11}{4})^2=\frac{121}{16}$, so $\frac{11}{4}$ is a square root of $\frac{121}{16}$.
Therefore: $\sqrt {\frac{121}{16}}=\frac{11}{4}$
