Answer:
31.47%
Explanation:
Total investment = 4000 + 3000 +9000 = $16,000
% of investment in A = 4000/16000 = 25%
% of investment in B = 3000/16000 = 18.75%
% of investment in Asset beta and risk-free asset = 100% - 25% -18.75% = 56.25%
Let the % of investment in asset with beta of 1.74 is A, % of investment in risk free asset is B.
We have the following simultaneous equations:
0.9 = (0.25 x 1.47) + (0.1875 x 0.54) + (A x 1.74) + (B x 0)
A+B = 56.25%
From the first equation, we get A = 24.78%
--> B = 56.25% - 24.78% = 31.47%
*** Note: Portfolio beta is the weighted sum of individual asset betas, according to the proportions of the investments in the portfolio
*** Note: Beta of risk free asset is 0