Answer:
Residua income = $80,000 
Step-by-step explanation:
Residual income is the excess of the controllable profit over the opportunity cost of capital invested. 
It is used to evaluate the financial performance of a division or department. 
The a positive residual value indicate a good performance, hence the higher the residual value the better 
It is computed as follows: 
Residual income = Controllable profit - (cost of capital× operating assets) 
Controllable profit = 560,000, 
Interest on capital = × 12% × 4,000,000 = 480,000 
Residual income = 560,000 - 480,000= 80,000 
Residua income = $80,000