The oil plant produces a batch of soybean oil. It is planned to produce 3.6 tons of oil per day, and it will be completed in 20 days. Now it has to be completed 4 days ahead of schedule. How many tons of oil does it need to produce per day? (Solved using ratio method)
油料厂生产一批豆油，计划每天出油3.6吨，20天完成，现在要提前4天完成，每天需出油多少吨？(用比例的方法解)
<gadget id="calculator">3.6 * 20</gadget>
<output>72</output>

<gadget id="calculator">20 - 4</gadget>
<output>16</output>

<gadget id="calculator">72 / 16</gadget>
<output>9/2 = around 4.5</output>

<result>9/2 = around 4.5</result>