There are six numbers lined up, their average is 52, the average of the first 4 numbers is 48, and the average of the last 4 numbers is 56, then what is the average of the middle two numbers.
有六个数排成一行，它们的平均数是52，其中前4个数的平均数是48，后4个数的平均数是56，那么中间两个数的平均数是多少．
<gadget id="calculator">56 * 4</gadget>
<output>224</output>

<gadget id="calculator">52 * 6</gadget>
<output>312</output>

<gadget id="calculator">48 * 4</gadget>
<output>192</output>

<gadget id="calculator">312 - 192</gadget>
<output>120</output>

<gadget id="calculator">224 - 120</gadget>
<output>104</output>

<gadget id="calculator">104 / 2</gadget>
<output>52</output>

<result>52</result>