Given that the three numbers are 2, 4, and 8, if one more number is added to make these four numbers form a ratio, then how many can this number be
已知三个数为2、4、8，若再添加一个数，使这四个数能组成一个比例，那么这个数可以是多少
<gadget id="calculator">2 * 8</gadget>
<output>16</output>

<gadget id="calculator">16 / 4</gadget>
<output>4</output>

<result>4</result>