(本小题满分12分) 鹰潭一中高三某班共有学生50人,其中男生30人,

(本小题满分12分)

鹰潭一中高三某班共有学生50人,其中男生30人,女生20人,班主任决定用分层抽样的方法在自己班上的学生中抽取5人进行高考前心理调查。

   (I)若要从这5人中选取2人作为重点调查对象,求至少选取1个男生的概率;

   (II)若男生学生考前心理状态好的概率为0.6,女学生考前心理状态好的概率为0.5, 表示抽取的5名学生中考前心理状态好的人数,求

答案

答案

相关题目

After the workers had all gained the new skill, the factory produced ______ dol
After the workers had all gained the new skill, the factory produced ______ dolls in 2012 as the year before.   A. more than twice as many                  B. twice as many as
某化学小组围绕燃烧与灭火的主题开展了相关活动。请你参
某化学小组围绕燃烧与灭火的主题开展了相关活动。请你参与完成: 【知识回忆】可燃物燃烧的必备条件是                            
A football match between Class Two and Class Three ________tomorrow afternoon.
A football match between Class Two and Class Three ________tomorrow afternoon. A. is held       B. was held           C. must be held    D. will be held
关于闭合电路的性质,以下说法正确的是 A.电源短路时,
关于闭合电路的性质,以下说法正确的是 A.电源短路时,输出电流无限大           B.电源断路时,路端电压无限大 C.外电路电阻越大,输出
Today, roller skating is easy and fun. But a long time ago, it wasn't easy at al
Today, roller skating is easy and fun. But a long time ago, it wasn't easy at all. Before 1750, the idea of skating didn't exist. That changed because of a man named Joseph Merlin. Merlin's work was m
—Jenny, which season is your favorite? — For me, summer is _______ of all
—Jenny, which season is your favorite? — For me, summer is _______ of all the seasons, because I like swimming in the river.      A.Exciting                       
若b<0<a,则下列各式不成立的是: A、a-b>0        
若b<0<a,则下列各式不成立的是: A、a-b>0            B、-a+b<0     C、ab<0           D、|a|>|b|
依次填出下面一段文字横线处的语句,衔接最恰当的一组是
依次填出下面一段文字横线处的语句,衔接最恰当的一组是 狗是忠义、勇敢而又聪明的动物。  , 。  ,  。  ,  ,使狗成为人的得力助手。 ①专

最新题目