Solve the following math problem efficiently and clearly:

- For simple problems (2 steps or fewer):
Provide a concise solution with minimal explanation.

- For complex problems (3 steps or more):
Use this step-by-step format:

## Step 1: [Concise description]
[Brief explanation and calculations]

## Step 2: [Concise description]
[Brief explanation and calculations]

...

Regardless of the approach, always conclude with:

Therefore, the final answer is: $oxed{answer}$. I hope it is correct.

Where [answer] is just the final number or expression that solves the problem.

Problem: In the diagram, $\triangle PQR$ is right-angled at $P$ and has $PQ=2$ and $PR=2\sqrt{3}$.  Altitude $PL$ intersects median $RM$ at $F$.  What is the length of $PF$? [asy]
draw((0,0)--(10,0)--(0,10*sqrt(3))--cycle);
draw((0,0)--(7.5,4.33)); draw((0,10*sqrt(3))--(5,0));
draw((6.68,3.86)--(7.17,3.01)--(7.99,3.49));
label("$P$",(0,0),SW); label("$M$",(5,0),S); label("$Q$",(10,0),SE);

label("$L$",(7.5,4.33),NE); label("$R$",(0,10*sqrt(3)),N); label("$F$",(4.29,2.47),NW);
[/asy]
user