a proportional fee based on the final sale price与最终的销售价格成比例的费用

Suicide rates are proportional to the size of the city.自杀率和城市的大小成比例。

Loss of weight is directly proportional to the rate at which the disease is progressing.体重减轻的幅度与病情加重的程度成正比。

Your solicitor's fee will be proportional to the cost of the house.律师费将与房屋的价格成比例。