The mean of the complete portfolio as a function of the proportion invested in the risky portfolio (y) is: E(rC) = (l –y)rf+yE(rP) =rf+y[E(rP) –rf ] = 4.5 +y(13.85 – 4.5) SettingE(rC ) = 13%y= .9094 (90.94% in the risky portfolio) 1 –y= .0906 (9.06% in T-bills) To prevent rounding error, we use the spreadsheet with the calculation of the previous parts of the problem to compute the proportion in each asset in the complete portfolio: σ(c)0.281286674 = (13% – 4.5%)/Sharpe ratio(risky portfolio) w(risky portfolio)0.909406301 =σ(c)/σ(risky portfolio) Proportion of stocks in complete portfolio w(s) =w(risky portfolio)*% in stock of the risky portfolio = 0.792876728 = 79.29% Proportion of bonds in complete portfolio w(s) =w(risky portfolio)*% in bonds the of risky portfolio = 0.116529573 = 11.65%