While I tagged this question homework, it's not really homework. I'm really studying for a test and don't understand how to do something. I have the answer to the question, so the important part is for my to understand how to get there.
X has distribution
X = Y-3 Find:
P(Y>11|Y>7) Which I know is equals to:
(1-P(X<8))/(1-P(X<4)) = (1-Fx(8))/(1-Fx(4))
I have been told that
Fx(a) = 1-e^(-a/4)-(a/4)*e^(-a/4)
So I can clearly solve the problem now it's just algebra. But how do we know what Fx(a) equals???