There are four numbers, choose three of them each time, calculate their average, add another number, calculate four times in this way, and get the following four numbers respectively: 72, 98, 136, 142, So, what is the average of the original four numbers?
有四个数，每次选取其中三个数，算出它们的平均数，再加上另外一个数，用这种方法计算了四次，分别得到以下四个数：72，98，136，142，那么，原来四个数的平均数是多少．
<gadget id="calculator">224 / 4</gadget>
<output>56</output>

<result>56</result>