Xiaohua was practicing the sum of natural numbers, starting from 1, and counting, he found that he had repeated a number. In this case, he averaged all the numbers he counted and the result was 7.4, what was the number he repeated.
小华在练习自然数求和，从1开始，数着数着他发现自己重复数了一个数．在这种情况下，他将所数的全部数求平均，结果为7.4，他重复的那个数是多少．
<gadget id="calculator">0.4 * 15</gadget>
<output>6</output>

<result>6</result>