What is x^2? Is it a random variable or just a constant? Is it related in some way to the x_i's?
I know how to do it the other way, but now it's asking me to do it this way and i'm confused.
Also, show how:
Lastly, show how:
I don't quite understand the expanding and/or simplifying i'm supposed to do. Any help is greatly appreciated.
Your notation is a little confusing.
Are you trying to find sigma^2 * x^2 or are you trying to find the variance of the random variable x^2?
You need to really fix this up before we continue because it is full of ambiguities.