So now how do i get a random number in the inclusive range 0.0 to 1.0, for example?
Just use Rnd(0,1). Never concerned myself with all that inclusive/exclusive lark. When you're returning a double the chances of that double being exactly 1 would be miniscule anyway.
Just ran a couple of hundred iterations and the highest I got was 0.99442527370318512. Do you need it more precise than that?