In a ratio, if the two inner terms happen to be reciprocals of each other, one of the outer terms is 4.5, and what is the other outer term.
在一个比例当中，如果两内项恰好互为倒数，其中一外项是4.5，另一个外项是多少．
<gadget id="calculator">1 / 4.5</gadget>
<output>0.222222</output>

<result>0.222222</result>