Am I using this ROR Formula Correctly?

[gaming_mouse]

I am using BruceZ's ror forumula for a random walk problem and I want to double check that the formula I am using is the correct one for this type of problem, and also that I have applied it correctly.

BruceZ's ROR Formula Post

Imagine you start with 50 units and play a coin flip in which you win 1.1 units 50% of the time and lose 1 unit 50% of the time.

EV = (1.1)*.5 + (-1)*.5 = .05
Var = ( (1.1)^2*.5 + (-1)^2*.5 ) - .05^2 = 1.1025
SD = 1.05

ror = exp(-2*.05*50/1.1025) = 0.0107

Is this result accurate for the problem described?

Thanks,
gm