View Full Version : Order Statistics problem


mobius0
07-16-2009, 11:08 PM
Let X1...Xn be independent, identically, distributed random variables. Determine the cumulative distribution functions of X(k),n, the kth largest of n observations. Compute the pdf in the case n=5, k=4 when X1...X5 are standard uniform random variables.

What I have attempted:
Set X(k),n, = kth largest
summation from j=k to n (Prob(X(j-1)<a and X(j)>a)
Using the cdf and binomial theorem I got
summation from j=k to n NCJ (1-Fx(a))^j (Fx(a))^n-j
I know this can't be right.. Where am I going wrong?

Thanks.

vinux
07-17-2009, 01:25 AM
The following link will help
http://en.wikipedia.org/wiki/Order_statistic