You seem to understand it correctly.
makes no sense, because there is no value given. It's undefined here.
How does one complete a summing operation where
and
and
a sum like
and for
where i is the index
i expanded it like this:
and in this case n = 4
My question, assuming I expanded correctly, stands thus: since the set of X has only 3 elements so how do I compele this operation?
thanks!