document.write( "Question 1205407: Suppose that X and Y Have the following joint probability distribution\r
\n" ); document.write( "\n" ); document.write( "f(x,y) x 2 4
\n" ); document.write( " 1 0.10 0.15
\n" ); document.write( "y 3 0.20 0.30
\n" ); document.write( " 5 0.10 0.15\r
\n" ); document.write( "\n" ); document.write( "a. Find the marginal distribution of X.
\n" ); document.write( "b. Find the marginal distribution of Y.
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Algebra.Com's Answer #845485 by moonwhisperer(1)\"\" \"About 
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Soln : marginal of x has two values for x=2 and x=4\r
\n" ); document.write( "\n" ); document.write( "For x = 2, we need to find sum of all y values over x=2
\n" ); document.write( "i.e. (2,1)+(2,3)+(2,5) = 0.1 + 0.2 + 0.1 = 0.4\r
\n" ); document.write( "\n" ); document.write( "For For x = 4, we need to find sum of all y values over x=4
\n" ); document.write( "i.e. (4,1)+(4,3)+(4,5) = 0.15 + 0.3 + 0.15 = 0.6 \r
\n" ); document.write( "\n" ); document.write( "To check marginal pdf of x sum to 1 = 0.4+ 0.6 \r
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\n" ); document.write( "\n" ); document.write( "Similarly,
\n" ); document.write( "marginal of y has three values for y=1, y=3 and y=5\r
\n" ); document.write( "\n" ); document.write( "For y=1, we need to find sum of all x values over y=1
\n" ); document.write( "i.e. (2,1)+(4,1) = 0.1 + 0.15 = 0.25\r
\n" ); document.write( "\n" ); document.write( "For y=3, we need to find sum of all x values over y=3
\n" ); document.write( "i.e. (2,3)+(4,3) = 0.2 + 0.3 = 0.5\r
\n" ); document.write( "\n" ); document.write( "For y=5, we need to find sum of all x values over y=5
\n" ); document.write( "i.e. (2,5)+(4,5) = 0.1 + 0.15 = 0.25\r
\n" ); document.write( "\n" ); document.write( "To check marginal pdf of y sum to 1 = 0.25+ 0.5 + 0.25 \r
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