采用简单随机抽样从含有6个个体的总体中抽取一个容量为3的样本,个

采用简单随机抽样从含有6个个体的总体中抽取一个容量为3的样本,个体前两次未被抽到而第三次被抽到的概率是(   )

A.         B.         C.         D.

答案

分析:本题考查与抽样有关的概率问题.

解:由概率乘法公式可知P=··=.

答案:C

相关题目

下列关于地球自转的叙述,不正确的是(    ) A.自转的方
下列关于地球自转的叙述,不正确的是(    ) A.自转的方向是自西向东                        B.自转的周期约为24小时 C.地球绕着地轴的旋转
It was ______they reached the camp site. A. not until midnight that  B. until m
It was ______they reached the camp site. A. not until midnight that  B. until midnight      C. midnight       D. when midnight  
 On no account can parents always ________ with the children, otherwise they w
 On no account can parents always ________ with the children, otherwise they will become more greedy and come up with more unreasonable requests.    A. disagree             B. stick
在实验室中,下列除去杂质的方法正确的是           
在实验室中,下列除去杂质的方法正确的是                     A.溴苯中混有溴,加入KI溶液,振荡,用汽油萃取出碘 B.乙烷中混有乙烯,
The head of the shop came ___ to see ___. A. up; what was the matter  B. up; wh
The head of the shop came ___ to see ___. A. up; what was the matter  B. up; what the matter was   C. along; what’s the matter D.down; what the matter was
 对离子反应:xR2++yH++O2===mR3++nH2O,下列说法中,错误的
 对离子反应:xR2++yH++O2===mR3++nH2O,下列说法中,错误的是 A. m=4,R3+是氧化产物                    B. x=y=m=4,n=2 C. 该反应中R2+得
第一次国共合作实现的根本原因是(   )A 中国革命的性质
第一次国共合作实现的根本原因是(   )A 中国革命的性质                     B 共产国际的帮助  C 孙中山真诚希望共产党同他合作
When should people be made to retire? 55? 65? Should there be a compulsory (强
When should people be made to retire? 55? 65? Should there be a compulsory (强制的) age limit? Many old people work well into their 70s and 80s, running families, countries or corporations. Other