The average of three numbers is 78, plus one more number, the average of these four numbers is 82, so what is the fourth number?
三个数的平均数是78，再加上一个数，这四个数的平均数是82，那么第四个数是多少？
<gadget id="calculator">82 * 4</gadget>
<output>328</output>

<gadget id="calculator">78 * 3</gadget>
<output>234</output>

<gadget id="calculator">328 - 234</gadget>
<output>94</output>

<result>94</result>