Sorry, it was a stupid question. You can ignore it. But it was a good LATEX practice for me though.
In the text, for
We have and ; therefore,
I then did that transformation [tex]Y=X-r{/math] to obtain
I then found the MGF to be:
I then tried us use the MGF to find and
and
therefore
So here's my question:
Why does
and
but
Var(Y)=Var(X)?