Question 1204574: Suppose that in a casino game the payout is a random variable X. If X is positive, you gain money, if negative, you lose. Let p(i) = P(X = i) and suppose that
p(0)= 1/4, p(1)=p(-1)= 147/520, p(2)=p(-2)= 9/104 and p(3)=p(-3) = 3/520.
Given that a player playing the game wins a positive amount, compute the conditional probability that...
... X = 1: ?
... X = 2: ?
... X = 3: ?
Could you please answer my question above?
I tried something like this but I am not sure about adding 0:
P(0)+P(1)+P(2)+P(3)=325/520
X=1 -> 147/325
X=2 -> 9/65
X=3 -> 3/325
Thank you very much for your effort!
Found 2 solutions by greenestamps, ikleyn:
Answer by greenestamps(13200)   (Show Source):
Answer by ikleyn(52803)  (Show Source):
You can put this solution on YOUR website! .
It is interesting:
In common use in English language, zero is unsigned, that is, it is neither positive nor negative.
In typical French mathematical usage, zero is both positive and negative.
Source:
https://math.stackexchange.com/questions/26705/is-zero-positive-or-negative#:~:text=In%20common%20use%20in%20English,is%20both%20positive%20and%20negative.
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I wrote this my notice above not to disprove somebody' solution,
but only to show that in Math, some basic notions/conceptions are based on existing agreements,
not only on axioms. It may seem, that at this circumstances, Math can not exist
as whole logical construction - nevertheless, it DOES EXIST.
Probably, there are some footprints in your education from French math,
since you are not confident, if 0 (zero) is positive or not.
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