After the mid-term exam, Xiaoqiao counted the average math score of the class, and the average score was 88.4 points. During the review, she found that she had mistaken a classmate's score of 89.5 points for 80.5 points. After recalculation, the class average score was 88.7 points. How many people are there in this class?
期中考试后，小巧统计了班级的数学平均成绩，平均成绩是88.4分，在复查时，她发现把一个同学的分数89.5分误看成了80.5分，重新计算后，班级平均成绩为88.7分．问这个班级共有多少人？
<gadget id="calculator">89.5 - 80.5</gadget>
<output>9</output>

<gadget id="calculator">88.7 - 88.4</gadget>
<output>0.3</output>

<gadget id="calculator">9 / 0.3</gadget>
<output>30</output>

<result>30</result>