iv$.$ A portfolio has an expected rate of return of $0\mathrm{.}15$ and a standard

deviation of $0\mathrm{.}15.$ The risk$-$free rate is $6$ percent. An investor has the

following utility function: $U=E(r)-(\frac{A}{2})s^2.$ Which value of A makes

this investor indifferent between the risky portfolio and the risk$-$free

asset?

$[5$ marks$]$