The number of trees planted by four greening groups in a certain school in one day is as follows: 10, 10, x, 8. Given that the mode of this set of data is equal to the mean, what is the median of this set of data?
某校四个绿化小组一天植树的棵数如下：10，10，x，8．已知这组数据的众数与平均数相等，那么这组数据的中位数是多少．
<gadget id="calculator">10 + 10</gadget>
<output>20</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<result>10</result>