In a trapezoidal wheat field, the upper base is 76 meters, the lower base is 120 meters, and the height is 50 meters. A total of 14.7 tons of wheat are harvested. How many tons of wheat are harvested per hectare on average?
一块梯形麦田，上底是76米，下底是120米，高50米，一共收小麦14.7吨，平均每公顷收小麦多少吨？
<gadget id="calculator">76 + 120</gadget>
<output>196</output>

<gadget id="calculator">50 / 2 / 10_000</gadget>
<output>1/400 = around 0.0025</output>

<gadget id="calculator">196 * (1/400)</gadget>
<output>49/100 = around 0.49</output>

<gadget id="calculator">14.7 / (49/100)</gadget>
<output>30</output>

<result>30</result>