Markowitz Portfolio Model. Consider the stock return scenarios for Apple Computer $($APPL$),$ Advanced Micro Devices $($AMD$),$ and Oracle Corporation $($ORCL$)$ shown in the file of StockReturn$1$:

a$.$

Develop the Markowitz portfolio model for these data with a required expected return of $25\%.$ Assume that the eight scenarios are equally likely to occur.

b$.$

Solve the model developed in part $($a$).$

c$.$

Vary the required return in $1\%$ increments from $25\%$ to $30\%$ and plot the efficient frontier.