【判断题】【消耗次数:1】
随机变量只有离散型和连续型。
正确
错误
参考答案:
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相关题目
【判断题】 离散型随机变量就是取值只有有限个的随机变量。
①  正确
②  错误
【判断题】 二维随机变量也分离散型和连续型。
①  正确
②  错误
【判断题】 连续型随机变量均有方差存在
①  正确
②  错误
【判断题】 任意连续型随机变量均有方差存在
①  正确
②  错误
【判断题】 随机变量X的取值为不可列无穷多,则X必为连续型随机变量
①  正确
②  错误
【单选题】 设连续型随机变量的密度函数为,则当()时,为随机变量数学期望.
①  收敛
②  为有界函数
③ 
④  绝对收敛
【判断题】 每一个连续型随机变量均有方差存在。
①  正确
②  错误
【判断题】 二维离散型随机变量的取值是有限个或可列个。
①  正确
②  错误
【单选题】 连续型随机变量X的密度函数f(x)必满足条件( ).
①  0f(x)1
②  f(x)为偶函数
③  f(x)单调不减
④  f(x)在负无穷到正无穷上积分为1
【判断题】 任一离散型随机变量的分布列满足:非负性,规范性
①  正确
②  错误
随机题目
【单选题】 It was not until he arrived in class _____ realized he had forgotten his book.
①  when he
②  that he
③  and he
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【判断题】 判断线上的内容是否正确:The teachers tried to __convince____ these students that they could solve the complicated problem, however, they just didn’t see the point.
①  正确
②  错误
【判断题】 判断线上的内容是否正确:For ten years the Greeks ___surrounded___ the city of Troy to separate it from the outside.
①  正确
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【单选题】 It was strange _______ she left without saying a word.
①  that
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③  why
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【单选题】 After the Minister of Education had finished speaking at the press conference, he was made ______ all sorts of awkward questions.
①  answer
②  answering
③  answered
④  to answer
【单选题】 The medicine is on sale everywhere.You can get it at _______ chemists.
①  each
②  some
③  certain
④  any
【单选题】 Medical research has shown that the widespread use of cigarettes contributes ___ the increaseof cancers.
①  to
②  for
③  with
④  towards
【单选题】 I _____ the right to appeal to higher authorities.
①  conserve
②  reserve
③  store
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①  prize
②  price
③  praise
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【单选题】 It s surprising that this idea took so long to _______.
①  add to
②  dispose of
③  catch on
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