Question 4 (Portfolio variance 1pt) Recall from class that the population variance and standard deviation of portfolio has the following 1 formulas. With two assets A and B : If the portfolio weight on asset A is wA and the the portfolio weight on asset BwB, then rp=Var(rp)=wArA+wBrB(wA)2Var(rA)+(wB)2Var(rB)+wAwBCov(rA,rB)+wBwACov(rA,rB). With more than two assets: If the portfolio weight on asset i is wi, and asset i has return ri, then rpVar(rp)=i=1Nwiri=i=1N(wi)2Var(ri)+iNjNwiwjCov(ri,rj) Suppose that an investor holds a portfolio of bonds X,Y and Z. Portfolio weights of the three assets are 20%,50% and 30%, respectively. The table below shows the variance-covariance matrix of the three assets. What is the standard deviation of the portfolio