For any two points $M$ and $N$ in the $XY$-plane, let $\overrightarrow { MN }$ denote the vector from $M$ to $N$, and $\overrightarrow { 0 }$ denote the zero vector. Let $P , Q$ and $R$ be three distinct points in the $XY$-plane. Let $S$ be a point inside the triangle $\triangle PQR$ such that $$\overrightarrow { SP } + 5 \overrightarrow { SQ } + 6 \overrightarrow { SR } = \overrightarrow { 0 }$$ Let $E$ and $F$ be the mid-points of the sides $PR$ and $QR$, respectively. Then the value of $$\frac { \text { length of the line segment } EF } { \text { length of the line segment } ES }$$ is $\_\_\_\_$ .
[1.15 to 1.25]
For any two points $M$ and $N$ in the $XY$-plane, let $\overrightarrow { MN }$ denote the vector from $M$ to $N$, and $\overrightarrow { 0 }$ denote the zero vector. Let $P , Q$ and $R$ be three distinct points in the $XY$-plane. Let $S$ be a point inside the triangle $\triangle PQR$ such that
$$\overrightarrow { SP } + 5 \overrightarrow { SQ } + 6 \overrightarrow { SR } = \overrightarrow { 0 }$$
Let $E$ and $F$ be the mid-points of the sides $PR$ and $QR$, respectively. Then the value of
$$\frac { \text { length of the line segment } EF } { \text { length of the line segment } ES }$$
is $\_\_\_\_$ .