Thursday 30 March 2017

probability - Is $mathbb{P}( X > Y) = mathbb{P}( X+k > Y+k )$ true, where X and Y are random variables?

My intuition tells me that $\mathbb{P}(X+k > Y+k) = \mathbb{P}(X > Y)$ should be true, since there (should?) be a bijection between every single result between these two probability distributions. But clearly there's a misunderstanding somewhere here, but I'm having trouble pinning it down.




A counterexample would be:
Suppose $X \sim \operatorname{Bin}(n, 0.5)$ and $Y \sim \operatorname{Bin}(n+1, 0.5)$.
$\mathbb{P}(X < Y) = \mathbb{P}(n-X < n+1-Y)$, since the probability distribution of $\operatorname{Bin}(n, 0.5)$ and $n - X$ should be exactly the same.



Thanks in advance for your help!

No comments:

Post a Comment

real analysis - How to find $lim_{hrightarrow 0}frac{sin(ha)}{h}$

How to find $\lim_{h\rightarrow 0}\frac{\sin(ha)}{h}$ without lhopital rule? I know when I use lhopital I easy get $$ \lim_{h\rightarrow 0}...