Talk:Joint probability distribution

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dont confuse random variables and events

split this formula into separate lines[edit]

\begin{align}

\mathrm{P}(X=x\ \mathrm{and}\ Y=y) = \mathrm{P}(Y=y \mid X=x) \cdot \mathrm{P}(X=x) = \mathrm{P}(X=x \mid Y=y) \cdot \mathrm{P}(Y=y) \end{align}. the last equals is very confusing where it tries to illustrate equivalency between x and y

Parsing errors in formulae[edit]

The formulae in the final version that I see (date 28th January 2009) are all erroneous. Returning to the previous version, where at least one can read the formulae!!!Noyder (talk) 12:27, 28 January 2009 (UTC)

I am totally out of my depth here and very perplexed!! The text of the article, when I refer to it, is full of red Parsing errors and the formulae do not appear. But I turn to 'History" and look at the previous and current version comparisons, "as if by magic" all the formulae appear without errors!!! Is my computer wrong or is there some problems with the article???? HELP!!! Noyder (talk) 12:39, 28 January 2009 (UTC)

Help with a problem[edit]

I'm trying to find the answer to a problem I'm having, I collect Yu-Gi-Oh! cards and I was making a spreadsheet to evaluate the probability of drawing cards out of packs, I have the ratios for each card and probability of pulling each out of a single pack but I'm finding it difficult to discover the probability of drawing every card I want out of the list. I'm guessing the solution has to do with Joint Probability. So far the data looks like this:
126 cards total in the set.
There are 9 cards per pack.
24 packs per box.
2 Secret Rares (probability of 1:31 packs)
10 Ultra Rares (probability of 1:12 packs)
10 Super Rares (probability of 1:6 packs)
22 Rares (probability of 5:7 packs)
82 commons (probability of 8:1 packs)

I want:
3 specific Commons
7 specific rares
1 specific super rare
1 specific ultra rare
1 specific secret rare

What are my odds of getting everything I want in a box of 24 packs?
174.24.99.41 (talk) 22:23, 27 July 2011 (UTC)Dragula42

Needs Examples[edit]

To anyone qualified to edit this article (definitely not me!), it is in serious need of some good examples and better description, as well as, perhaps, an explanation as to why this is important and where it fits in with the rest of statistics! — Preceding unsigned comment added by 99.181.61.118 (talk) 20:19, 2 August 2011 (UTC)