Question

（6分）某区为了解全区2800名九年级学生英语口语考试成绩的情况，从中随机抽取了部分学生的成绩（满分24分，得分均为整数），制成下表：

分数段（x分）	x≤16	17≤x≤18	19≤x≤20	21≤x≤22	23≤x≤24
人   数	10	15	35	112	128

【小题1】（1）填空：
①本次抽样调查共抽取了  ▲ 名学生；
②学生成绩的中位数落在 ▲ 分数段；
③若用扇形统计图表示统计结果，则分数段为x≤16的人数所对应扇形的圆心角为  ▲ °；
【小题2】（2）如果将21分以上（含21分）定为优秀，请估计该区九年级考生成绩为优秀的人数．

Answer 1

【小题1】（1）①300················································································· 1分
②21≤x≤22···················································································· 3分
③12······························································································ 4分
【小题2】2）2800×=2240（人）    5分

解析