want to understand why i got his one wrong please

Consider a discrete random variable, X, with pmf p(x). The variance of X is calculated using which of the following formulas? xIP (x1) + x2p (22) + +Inp (In) (21 - 14)2 p(21) + (2:2 - 14)2 p(22) + ... + (In - 1) p(In) n V zip (x1) + ap(22) + +up(In) None of the above