A stock has a beta of $1\mathrm{.}4$ and an expected return of $20\%.$The risk$-$free assets currently earns $3\mathrm{.}5\%.1.$ What is the expected return on portfolio that is equally invested in the two assets? $2.$ If a portfolio of the two assets has a beta of $0\mathrm{.}8,$ what is the portfolio weight of the risk$-$free assets? $3.$ If a portfolio of the two assets has an expected return of $8\%,$ what is its beta? $4.$ If a portfolio of the two assets has a beta of $2\mathrm{.}8,$ what is the portfolio weight of the risk$-$free assets?