Assuming that E[Sum X^2] = n(sigma^2 - mu^2), that E[Sigma X_bar^2] = n ((sigma^2/ n)- mu^2)

Assuming that E[)_, X?] = n(o? - #?), that E EX=n( -H? ), and that B [En, XX,] = EnX = n("-u? ), please simplify E[_ _, X?] - 26[_ _, XX,] +