Let Y be a random vector in R" (so it has n elements). The expected value of Y is defined as: EY EY2 EY = EYn i. Express the matrix product (Y - EY) (Y - EY)' elementwise. ii. Write the ijth element of the matrix in (i) in terms of Yi, Yj, EY, and EY;. iii. What is the expected value of the ijth element of the matrix in (i)? (Hint: it's one of the common expectations defined in lecture.) iv. The matrix of the expected values in (iii) is defined as the variance of the random vector Y. That is: varY = E (Y - EY) (Y - EY)