To calculate this result, we first need to calculate the portfolio value, then determine the weights for each stock, and then calculate the expected return. Finally, we determine the compounded rate after three years.

Portfolio Value: = sum of market values = 2,000 + 3,200 + 2,800 = 8,000

Portfolio Weights:
W_A = 2,000 / 8,000 = 0.25
W_B = 3,200 / 8,000 = 0.40
W_C = 2,800 / 8,000 = 0.35

Expected Return
ER_portfolio = Σ[(ER_stock)(W_{% of funds invested in each of the stocks})]
ER = w_RER_R + w_SER_S + w_TER_T, where ER = Expected Return and w = % invested in each stock.
ER = (0.25 × 17.0) + (0.40 × 8.0) + (0.35 × 13.0) = 12.0%

Expected Return after three years
= (1 + return)³ = (1.12)³ − 1 = 1.405 − 1 = 0.405, or 40.5%.