1 | x and z are random variables with distributions - one has n copies of each |
2 | y = S (zi=f(xi))/n is a random variable with a distribution ,even though we only have one value for y we can calculate properties of this distribution including most importantly the expected error in y |
3 | This is most importantly applied in case f(x)=x and the above allows one to calculate error in basic central limit theorem application to y = S xii/n |