Uncle Zhang planted corn in a trapezoidal field with a height of 150 meters, an upper bottom of 120 meters and a lower bottom of 140 meters, and harvested a total of 10,140 kilograms of corn. How many kilograms of corn are harvested on average per hectare?
张大伯在一块高150米，上底120米，下底140米的梯形地里种玉米，共收玉米10140千克．平均每公顷收玉米多少千克？
<gadget id="calculator">120 + 140</gadget>
<output>260</output>

<gadget id="calculator">150 / 2 / 10_000</gadget>
<output>3/400 = around 0.0075</output>

<gadget id="calculator">260 * (3/400)</gadget>
<output>39/20 = around 1.95</output>

<gadget id="calculator">10_140 / (39/20)</gadget>
<output>5_200</output>

<result>5_200</result>