The seventh grade of a certain middle school went out for a spring outing. Each class took a station wagon. On average, each station wagon carried 46.25 students. How many seventh grade classes does the school have?
某中学七年级外出春游，每个班乘坐一辆旅行车，平均每辆旅行车乘坐学生46.25人，则该校七年级有多少个班．
<result>4</result>