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beata
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Joined: April 15th, 2004, 12:27 pm

x, y normally distributed, x*y ? distributed

June 27th, 2006, 12:17 pm

hi guys,hoe can help me to remember some basic statistics?if x is ~N(0,sigma1), y is ~N(0,sigma2),which distribution does x*y have?
 
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Panang
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Joined: June 8th, 2006, 11:22 am

x, y normally distributed, x*y ? distributed

June 27th, 2006, 12:53 pm

If X~N(muX,sigmaX^2) and Y~N(muY,sigmaY^2) are independent normal random variables, then their product XY follows a distribution with density p given by p(z) = (1/(pi*sigmaX*sigmaY))*K0(mod(z) / sigmaX*sigmaY)where K0 is a modified Bessel function of the second kind.
 
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beata
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Joined: April 15th, 2004, 12:27 pm

x, y normally distributed, x*y ? distributed

June 27th, 2006, 1:16 pm

thnx Panang!Though some details:is mod(z) modulus(z)?and what if muX and muY are not equal to zero?
 
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PaperCut
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Joined: May 14th, 2004, 6:45 pm

x, y normally distributed, x*y ? distributed

July 8th, 2006, 6:08 am

QuoteOriginally posted by: PanangIf X~N(muX,sigmaX^2) and Y~N(muY,sigmaY^2) are independent normal random variables, then their product XY follows a distribution with density p given by p(z) = (1/(pi*sigmaX*sigmaY))*K0(mod(z) / sigmaX*sigmaY)where K0 is a modified Bessel function of the second kind.Are you sure ? It's late and I am sleepy, but what's up with the mod term?