$($Security market$$ line$)$You are considering the construction of a portfolio comprised of equal investments in each of four different stocks. The betas for each stock are found$$ below:

Asset

Beta

A

$2\mathrm{.}00$

B

$1\mathrm{.}05$

C

$0\mathrm{.}60$

D

$$ negative $1\mathrm{.}80$

$($Click on the icon in order to copy its contents into a spreadsheet.$)$

a$.$What is the portfolio beta for your proposed investment$$ portfolio?

b$.$How would a $25$ percent increase in the expected return on the market impact the expected return of your$$ portfolio?

c$.$How would a $25$ percent decrease in the expected return on the market impact the expected return on each$$ asset?

d$.$If you are interested in decreasing the beta of your portfolio by changing your portfolio allocation in two$$ stocks, which stock would you decrease and which would you$$ increase? $$ Why?