# beta distribution

• Nov 29th 2008, 12:53 PM
sp1705
beta distribution
can anyone tell me how to prove the mean and variance for the beta distribution function?
• Nov 29th 2008, 04:12 PM
mr fantastic
Quote:

Originally Posted by sp1705
can anyone tell me how to prove the mean and variance for the beta distribution function?

You need to calculate two things: \$\displaystyle E(X)\$ and \$\displaystyle E(X^2)\$.

It has what you need to know.
• Nov 30th 2008, 03:32 AM
sp1705
i realise that i need to calculate E(x) and E(x^2) but how do i integrate x*beta function to get E(x)? i really dont understand the gamma function thing the r symbol? any help?
• Nov 30th 2008, 10:49 AM
mr fantastic
Quote:

Originally Posted by sp1705
i realise that i need to calculate E(x) and E(x^2) but how do i integrate x*beta function to get E(x)? i really dont understand the gamma function thing the r symbol? any help?

Have you red the thread whose link I gave you? The details of the integration are all in there. Read it. What don't you undertsand?

"the gamma function thing the r symbol": Gamma function - Wikipedia, the free encyclopedia