Suppose $F(x)$ is any function that is differentiable for all real numbers $x$. Evaluate the following derivative. $\displaystyle{\frac{d}{dx} \left( F(x^{4}) \right) = }$ Enter the derivative of $F(x)$ as F'(x) using prime notation. Your answer should be in terms of $F'$ and other functions of the variable $x$.