皮皮学，免费搜题
登录
搜题
【简答题】
（本小题满分12分） 第26届世界大学生夏季运动会将于2011年8月12日到23日在深圳举行，为了搞好接待工作，组委会决定对礼仪小姐进行培训.已知礼仪小姐培训班的项目A与项目B成绩抽样统计表如下，抽出礼仪小姐 人，成绩只有 、 、 三种分值，设 分别表示项目A与项目B成绩．例如：表中项目A成绩为 分的共7+9+4＝20人．已知 且 的概率是 ． (I)求 ； (II)若在该样本中，再按项目B的成绩分层抽样抽出 名礼仪小姐，则 的礼仪小姐中应抽多少人？ (Ⅲ)已知 ， ，项目B为3分的礼仪小姐中，求项目A得3分的人数比得4分人数多的概率．
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【简答题】简述链接命令文件(·cmd文件)的功能。
【单选题】Which of the following statements is true?
A.
All vessels should carry at least one SART.
B.
SART should be stowed as high as possible according to the SOLAS Convention.
C.
SART can be mounted either on the compass deck or in the survival craft.
D.
SART can be fixed on a mother ship and a lifeboat, but it cannot be fixed on a life craft.
【单选题】Why did the author
A.
to meet the clerk
B.
to buy a gift card
C.
to buy some food
D.
to order a
【单选题】Why did the author become a writer?
A.
Partly because he had a father.
B.
Partly because of his father’s influence.
C.
Partly because his father was familiar with world writers.
D.
Partly because his father knew some great religious leaders.
【简答题】UCS是_()A. 户坐标系
相关题目：
【单选题】Why did the author
A.
to meet the clerk
B.
to buy a gift card
C.
to buy some food
D.
to order a