题目

根据短文内容回答问题。 Hi! Do you know the three children? They are in a happy family. Xiao Xue is a helpful girl. She is beautiful. She likes studying. She studies very hard. She gets up early and finishes her breakfast quickly .Then she rides her bike to school . Liu Xing is a little lazy. He gets up late and then washes his face, brushes his teeth in a hurry. Then he goes to the bus stop without breakfast. He usually plays basketball after school. In the evening, he seldom (很少)does homework. He goes to bed late. Xiao Yu is a lovely boy. He gets up very slowly and then 在某次数学小测验后，老师统计了所任两个班级的数学成绩，并制成下面的频率分布表，请你估计这两个班的本次数学测验的平均分为       .                分组 人数 频率 10 0.1 30 0.3 40 0.4 20 0.2 合计 100 1