There are four numbers, use the average of three of them, plus another number, calculate in this way, respectively get: 28, 36, 42, 46, then what is the average of the original four numbers.
有四个数，用其中三个数的平均数，再加上另外的一个数，按这样的方法计算，分别得到：28、36、42、46，那么原来四个数的平均数是多少．
<gadget id="calculator">28 + 36 + 42 + 46</gadget>
<output>152</output>

<gadget id="calculator">152 / 2 / 4</gadget>
<output>19</output>

<result>19</result>