In a ratio, two inner terms are known to be reciprocals of each other, if one of the outer terms is (4/7), then what is the other outer term.
在一个比例里，已知两内项互为倒数，如果其中一个外项为(4/7)，那么另一个外项为多少．
<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">1 / (4/7)</gadget>
<output>7/4 = around 1.75</output>

<result>7/4 = around 1.75</result>