Step-by-step explanation:
Given,
A portfolio has a E[r] = 12 %, and
A standard deviation ([tex]\sigma[/tex]) = 18 %
We know that,
Specify utility by U = E(r) – 0.5A[tex]\sigma^2[/tex]
U = 0.12– 0.5(A) × [tex]0.18^2[/tex]
= 0.12 - 0.5 × A × 0.0162
In order for the risky portfolio to be preferred to bills,
The following condition must have:
0.12 – 0.0162A > 0.07
⇒ A < [tex]\dfrac{0.05}{0.0162}[/tex] = 3.09
A must be less than 3.09 for the risky portfolio to be preferred to bills.
Thus, the required "option D) 3.09" is correct.