The above answer can be calculated as -
Let the expected return of stock C be X
Given, Portfolio amount = $ 48,000, Expected return on portfolio = 14.5 %
Amount of expected return of portfolio = $ 48,000 X 14.5 % = $ 6,960
Now, the returns from the remaining two stock will be calculated -
Return on Stock A = $ 16,700 X 18.7 % = $ 3,122.90
Return on Stock B = $ 2,710.4
Total return = $ 3,122.9 + $ 2,710.4 + X = $ 6,960
X = $ 1,126.70
Remaining amount of portfolio = $ 48,000 - $ 16700 - $ 24200 = $ 7100
Expected return on Stock C = $ 1,126.70 / 7,100 = 15.9%