Use one car to transport goods, 4 times in the morning, a total of 15.6 tons, and 3 times in the afternoon, 2.5 tons less than in the morning, how many tons are transported each time on average throughout the day?
用一辆汽车运货物，上午运4次，共运15.6吨，下午运3次，比上午少运2.5吨，全天平均每次运货多少吨？
<gadget id="calculator">15.6 - 2.5</gadget>
<output>13.1</output>

<gadget id="calculator">13.1 + 15.6</gadget>
<output>28.7</output>

<gadget id="calculator">4 + 3</gadget>
<output>7</output>

<gadget id="calculator">28.7 / 7</gadget>
<output>4.1</output>

<result>4.1</result>