Johann Van Aert has decided to use the following information to explain portfolio composition options that are available to his high net-worth client. 3 suitable portfolios are shown in the table below.

  

Help Johann determine the minimum-variance and optimal portfolios

Help Johann explain the advantage of the optimal portfolio to his client using the Sharpe ratio of each portfolio

Johann’s client has noted that she is not interested in investing all her monies in the optimal portfolio; she prefers a mix of 45% in a risk-free asset and the remainder in the optimal portfolio. Compute the allocation to each of the three asset classes in her preferred complete portfolio. All values must be shown.
 

T-bills Portfolio Alp Portfolio Sierra Portfolio Andes Exp Return 5.00% 5.50% 8.00% 9.00% 11.80% 8.75% 11.75% Sdevn Weight Weight bonds stocks 80% 20% 51% 49% 44% 56%