Answer: 
$158.40 
Explanation: 
For computation of amount of the cost of goods sold for this sale first we need to find out the Weighted Average Cost per unit which is shown below:- 
Weighted Average Cost per unit = ((10 units × $12) + (15 units × $14)] ÷ (10 + 15) 
= 330 ÷ $25 
= $ 13.20 per unit 
Cost of Goods Sold = Purchase per unit × Weighted Average Cost per unit 
= 12 units × 13.20 per unit 
= $158.40