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-Brian ([[User:Thomas34|Thomas34]] 00:23, 9 December 2008 (UTC))
 
-Brian ([[User:Thomas34|Thomas34]] 00:23, 9 December 2008 (UTC))
 
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This is the correct result but there are a few typos...
 
 
 
We know <math>f_X (a) = \frac{2}{3}</math> in this region from part a, and from the graph, <math>f_{XY} (a,y) = \{\frac{4}{3}, \ \ 0 \leq y \leq 1;  \ \ \ 0, \ \ \text{else}\}</math>.
 
 
So, dividing, <math>f_{Y|X}(y|a)= = \{2, \ \ 0 \leq y \leq .5;  \ \ \ 0, \ \ \text{else}\}</math>.
 

Latest revision as of 16:31, 9 December 2008

$ f_{y|x}(y|a)= \frac {f_{X,Y}(x,y)}{f_X(a)}\qquad \mathrm{Where}\ f_X(a) = f_X(x)\ \mathrm{for}\ 0<x<0.5 $

I'm not sure if this is right


I agree with your proposal, Arie. Let's finish this section of the problem:

$ f_{Y|X}(y|a)= \frac {f_{X,Y}(a,y)}{f_X(a)} $

We know $ f_X (a) = \frac{2}{3} $ from part a, and from the graph, $ f_{XY} (a,y) = \{\frac{4}{3}, \ \ 0.5 \leq y \leq 1; \ \ \ 0, \ \ \text{else}\} $.

So, dividing, $ f_{Y|X}(y|a)= = \{2, \ \ 0.5 \leq y \leq 1; \ \ \ 0, \ \ \text{else}\} $.

$ E(Y|X=a) = \frac{3}{4} $, and $ Var(Y|X=a) = \frac{1}{48} $, since $ f_{Y|X}(y|a) \frac{}{} $ has a uniform PDF.

-Brian (Thomas34 00:23, 9 December 2008 (UTC))

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