In a proportional formula, the two outer terms are the smallest prime number and the smallest composite number, one inner term is 3.2, and the other inner term is what.
在一个比例式中，两个外项分别是最小的质数和最小的合数，一个内项是3.2，另一个内项是多少．
<gadget id="calculator">4 / 3.2</gadget>
<output>1.25</output>

<gadget id="calculator">2 * 1.25</gadget>
<output>2.5</output>

<result>2.5</result>