Determine the range of values of $P$ for which equilibrium of the block shown in the figure is maintained. Given: $F = 1,400 \text{ N}$, $\theta = 45^\circ$, $\mu_s = 0.2$, and $\mu_k = 0.15$.
The range of values of $P$ is $\boxed{\phantom{0000}} \text{ N} \le P \le \boxed{\phantom{0000}} \text{ N}$.