Answer
$b=\displaystyle \frac{1}{4}$
Work Step by Step
$\displaystyle \frac{1}{2}=(\frac{b}{4})^{1/4}\qquad \color{blue}{\text{ ... }/(...)^{4} }$
$(\displaystyle \frac{1}{2})^{4}=\frac{b}{4}\qquad \color{blue}{\text{ ... }/\times 4 }$
$4(\displaystyle \frac{1}{2})^{4}=b$
$4 (\displaystyle \frac{1}{16})=b$
$\displaystyle \frac{1}{4}=b$
