There are four numbers whose average is 5. If one of the numbers 1 is changed to 12, what is the average of them?
有四个数，它们的平均数是5，把其中一个数1改为12，那么它们的平均数变为多少．
<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<gadget id="calculator">12 - 1</gadget>
<output>11</output>

<gadget id="calculator">20 + 11</gadget>
<output>31</output>

<gadget id="calculator">31 / 4</gadget>
<output>31/4 = around 7.75</output>

<result>31/4 = around 7.75</result>