The two inner terms of a ratio are both (3/4), and the two outer terms are the reciprocals of x and 0.8 respectively.
一个比例的两个内项都是(3/4)，两个外项分别是x和0.8的倒数．
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">(3/4) * (3/4)</gadget>
<output>9/16 = around 0.5625</output>

<gadget id="calculator">1 / 0.8</gadget>
<output>1.25</output>

<gadget id="calculator">(9/16) / 1.25</gadget>
<output>0.45</output>

<result>0.45</result>