Given:

$E(R_1)=0\mathrm{.}12$

$E(R_2)=0\mathrm{.}16$

$E({}_1)=0\mathrm{.}01$

$E({}_2)=0\mathrm{.}05$

for the expected returns of a two$-$stock portfolio to three decimal places and answers for expected standard deviations of a two$-$stock portfolio to four decimal places.

a$.r_{1,2}=1\mathrm{.}00$

Expected return of a two$-$stock portfolio:

Expected standard deviation of a two$-$stock portfolio:

b$.r_{1,2}=0\mathrm{.}75$

Expected return of a two$-$stock portfolio:

Expected standard deviation of a two$-$stock portfolio:

c$.r_{1,2}=0\mathrm{.}25$

Expected return of a two$-$stock portfolio:

Expected standard deviation of a two$-$stock portfolio:

d$.r_{1,2}=0\mathrm{.}00$

Expected return of a two$-$stock portfolio:

Expected standard deviation of a two$-$stock portfolio:

e$.r_{1,2}=-0,25$

Expected return of a two$-$stock portfolio:

Expected standard deviation of a two$-$stock portfolio:

f$.r_{1,2}=-0,75$

Expected return of a two$-$stock portfolio:

Expected standard deviation of a two$-$stock portfolio:

g$.r_{1,2}=-1\mathrm{.}00$

Expected return of a two$-$stock portfolio:

Expected standard deviation of a two$-$stock portfolio: