There are seven numbers, arranged from left to right in order from largest to smallest. The sum of these seven numbers is 258.6, the average of the first four numbers is 58.5, and the average of the last four numbers is 18.4. What is the median of this group of data?
有七个数，按从大到小的顺序从左至右依次排列着．这七个数的总和是258.6，其中前四个数的平均数是58.5，后四个数的平均数是18.4，这组数据的中位数是多少？
<gadget id="calculator">58.5 * 4</gadget>
<output>234</output>

<gadget id="calculator">18.4 * 4</gadget>
<output>73.6</output>

<gadget id="calculator">73.6 - 258.6</gadget>
<output>-185</output>

<gadget id="calculator">234 + (-185)</gadget>
<output>49</output>

<result>49</result>