What is the median of the data set of 15, 23, 24, 36, 42, 45?
15，23，24，36，42，45这组数据的中位数是多少．
<gadget id="calculator">24 + 36</gadget>
<output>60</output>

<gadget id="calculator">60 / 2</gadget>
<output>30</output>

<result>30</result>