In such case: P(A|B) = P(A|B,C) = P(A)/P(B)
----- Original Message -----
From: "Nicola Novielli" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, June 17, 2009 3:51 PM
Subject: Query on conditional probabilities: errata corrige
Thanks to the people that let me note the error in my notation.
In the first part of my question I actually meant:
"
Let’s say we have three events A, B and C where A is a subset of B and B is
a
subset of C. This implies that A is a subset of C.
"
Cheers
Nico
----------------------------
Dear allstatters,
I have a question on probabilities.
Let’s say we have three events A, B and C where C is a subset of B and B is
a
subset of A. This implies that C is a subset of A.
When it comes to consider probabilities we can calculate
P(B|C)
P(A|B,C)
Can we calculate P(A|B)? Does this exist and is this different from
P(A|B,C)?
What it seems to me is that “A|B” actually implies conditioning on C, thus
“A|B
and C” is actually correct, and “A|B” is simply a not complete notation. So,
writing P(A|B) is actually identical to P(A|B,C) a part from the clarity of
conditions.
Con anyone confirm or correct these statements?
Thanks a lot in advance for any answer.
Nico
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