1. The problem asks to evaluate the expression $\left(\frac{1}{4}\right)^{-\frac{1}{2}}$. 2. Recall that for any expression $a^b$, when $b$ is negative, $a^b = \frac{1}{a^{-b}}$. 3. Apply this to $\left(\frac{1}{4}\right)^{-\frac{1}{2}}$ to get $\left(\frac{1}{4}\right)^{-\frac{1}{2}} = \frac{1}{\left(\frac{1}{4}\right)^{\frac{1}{2}}}$. 4. Next, evaluate $\left(\frac{1}{4}\right)^{\frac{1}{2}}$ which is the square root of $\frac{1}{4}$. 5. The square root of $\frac{1}{4}$ is $\frac{1}{2}$. 6. Substitute back: $\frac{1}{\left(\frac{1}{4}\right)^{\frac{1}{2}}} = \frac{1}{\frac{1}{2}}$. 7. Dividing by $\frac{1}{2}$ is the same as multiplying by $2$, so $\frac{1}{\frac{1}{2}} = 2$. **Final answer:** $\boxed{2}$