There are four numbers. Starting from the second, each number is 3 greater than the previous number. It is known that the average of these four numbers is 24.5. What is the largest number among them?
有四个数，从第二个起，每个数都比前一个数大3，已知这四个数的平均数是24.5，其中最大一个数是多少？
<gadget id="calculator">24.5 * 4</gadget>
<output>98</output>

<gadget id="calculator">98 - 3 - 6 - 9</gadget>
<output>80</output>

<gadget id="calculator">1 + 1 + 1 + 1</gadget>
<output>4</output>

<gadget id="calculator">80 / 4</gadget>
<output>20</output>

<gadget id="calculator">20 + 9</gadget>
<output>29</output>

<result>29</result>