Bob Marley has an equal amount invested in each of the following four securities;

Securty

K

Expected Annual Rate

$0\mathrm{.}13$

T

$0\mathrm{.}23$

$0\mathrm{.}35$

G

a$.$ Bob plans to sell security Z and use the proceeds to purchase a new security that has the same expected return as the current portfolio. What will happen to the expected return for the investor's new portfolio, compared to the current portfolio? Explain.

b$.$ If Bob intends to sell security K instead, and use the proceeds to purchase a new security that has an expected retur of $9\%.$ Compared to the investor's initial portfolio, what will be the expected return for the investor's revised portfolio? Explain.