If a matrix looks like this

.....-3 0 3 <-x

....0 0 0 0.2

y..1 0 0.2 0.1

....2 0.3 0.2 0

how do u calculate the variance for x, given y = 2?

How do u even find the probability function for x in this case with a conditional?

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- Nov 24th 2009, 03:45 AMAllan89aConditional variance
If a matrix looks like this

.....-3 0 3 <-x

....0 0 0 0.2

y..1 0 0.2 0.1

....2 0.3 0.2 0

how do u calculate the variance for x, given y = 2?

How do u even find the probability function for x in this case with a conditional? - Nov 24th 2009, 09:32 AMANDS!
Do you know how to find the marginals of a Random Variable X (or Y)? What you want to do is not possible otherwise.

- Nov 25th 2009, 01:19 AMAllan89a
You mean the marginal probability? I think you sum the rows and columns in the 3x3 matrix to get that.