The product of exponential and a uniform random variables

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SUMMARY

The discussion focuses on proving that the random variable Z = U(X+Y) has the same distribution as X, where X and Y are independent random variables following an exponential distribution with parameter λ, and U is uniformly distributed on (0,1). It is established that X+Y follows a gamma distribution, specifically gamma(2,λ). The solution involves computing the Laplace transform of Z, denoted as \(\tilde{Z}(s) \equiv Ee^{-sZ}\), and conditioning on U to facilitate the analysis.

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  • Understanding of exponential distributions, specifically exp(λ).
  • Knowledge of gamma distributions, particularly gamma(2,λ).
  • Familiarity with Laplace transforms and their applications in probability theory.
  • Concept of conditioning in probability, especially with independent random variables.
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  • Explore conditioning techniques in probability, focusing on independent random variables.
  • Investigate the implications of uniform distributions in the context of random variable transformations.
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Homework Statement



I'm trying to show that U(X+Y) = X in distribution, where X and Y are independent exp(λ) distributed and U is uniformly distributed on (0,1) independent of X+Y.

Homework Equations


The Attempt at a Solution


X+Y is gamma(2,λ) distributed. But I can't figure out how to deal with this product.
 
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MathBubble said:

Homework Statement



I'm trying to show that U(X+Y) = X in distribution, where X and Y are independent exp(λ) distributed and U is uniformly distributed on (0,1) independent of X+Y.


Homework Equations





The Attempt at a Solution


X+Y is gamma(2,λ) distributed. But I can't figure out how to deal with this product.

Get the distribution of Z = U(X+Y) by computing its Laplace transform
\tilde{Z}(s) \equiv Ee^{-sZ}.
Hint: condition on U.

RGV
 

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