Random actions

I'm working on very unpredicrable AI for my enemy characters and want them to act randomly in different situations. Simply put, I want to make the enemy to either attack or take few steps backwards when they get close to player. I can make them do that with 50/50 chance by giving them command to randomly jump into states 1 and 2 with "Random(1,2)" command.

Now I'm wondering how should change the chances between those two, making the jump into state 1 to have 75% percent chance and state 2 to 25%?

I know this is kinda difficult to explain, and I can't really upload a .capx because the project is so full of things it would take way too long to cut everything unnecessary out.

I hope someone can help me with this :)

There may be more elegant solutions, but you can always (pseudo code, bare with me):

set a local variable to int(random(3))
..local variable <=2 
....-> Jump state = 1
..local variable = 3
....-> Jump state = 2