1. The problem involves understanding the concept of General Average in maritime law, which spreads the risk of loss among all cargo owners. 2. The key formula is that the fraction of the total cargo value lost is shared proportionally by all owners. In this example, one-half of the cargo value must be thrown overboard. 3. This means if the total cargo value is $V$, the value lost is $\frac{1}{2}V$. 4. Each owner loses a fraction of their cargo value proportional to this loss. If an owner has cargo worth $v_i$, their loss is $\frac{1}{2}v_i$. 5. This ensures fairness by distributing the loss equally relative to each owner's stake. 6. Therefore, the fraction of loss per owner is $\frac{1}{2}$ of their cargo value. Final answer: Each owner loses half of their cargo value, i.e., $\frac{1}{2}v_i$.