Suppose we have a data set with only two observations, y1 and y2. The general formula for the sample average is: sample average=1/2(y1+y2) Suppose y1 and y2 are sampled from the population in such a way so that they are correlated with each other. in particular, suppose that cov(y1,y2)= \(\gamma\) and does not equal zero. does this change wheter or not the sample average is unbiased. why or why not?