Thread: integration of pdf of gamma distribution

the pdf of gamma distribution is [e^(-y/a)*(y/a)^(n-1)] / (a*(n-1)!)
I'm trying to find P(Y>5) by integration the pdf from 5 to Infinity but it doesn't work out well...

Originally Posted by godai

the pdf of gamma distribution is [e^(-y/a)*(y/a)^(n-1)] / (a*(n-1)!)
I'm trying to find P(Y>5) by integration the pdf from 5 to Infinity but it doesn't work out well...

See the cdf given here Gamma distribution - Wikipedia, the free encyclopedia for why you're probably having trouble ....