In a ratio, the product of two outer terms is 6.3, one inner term is 1.5, and what is the other inner term.
在一个比例里，两个外项的积是6.3，一个内项是1.5，另一个内项是多少．
<gadget id="calculator">6.3 / 1.5</gadget>
<output>4.2</output>

<result>4.2</result>