Hmm that's not really correct :sBut for the discrete case I'm a little stuck as to how to start...
ay help would be much appreciated
It is not specified whether X have a continuous or a discrete distribution. And if it has integer values or not.
The problem with what you've done is that the have to be ordered, that is to say that they have to be in an increasing order.
Why ? Because you're considering . This means that you consider all the that are .
By summing over the i, you don't include this important information.
You should do something like :
(it's a summation over the x)
FYI, discrete distributions can also have a cdf.
I find your problem quite confusing... Is it really the way it has been posed ?