$\left.\begin{array}{ll}{[\text { Intersecting lines, angle between them }]} \\ {[\quad \text { Prism (other) }}\end{array}\right]$

On the lateral edges $A A 1, B B 1$, and $C C 1$ of the triangular prism $A B C A 1 B 1 C 1$, points $M, N$, and $P$ are located such that $A M: A A 1 = B 1 N: B B 1 = C 1 P: C C 1 = 3: 4$. On the segments $C M$ and $A 1 N$, points $E$ and $F$ are located such that $E F \| B 1 P$. Find the ratio $E F: B 1 P$.