问题
单项选择题
设二维随机变量X和Y相互独立，其概率分布为
则下列式子正确的是______．
答案
参考答案：C
解析：[考点提示] 关键是正确分解事件{X=Y}．
[解题分析] 由X与Y相互独立知
[*]
故应选C．
[评注1] 本题考查二维离散型随机变量的概率计算．
[评注2] X与Y同分布时，不一定有X=Y或P{X=Y
搜题请搜索小程序“爱下问搜题”
设二维随机变量X和Y相互独立，其概率分布为
则下列式子正确的是______．
参考答案：C
解析：[考点提示] 关键是正确分解事件{X=Y}．
[解题分析] 由X与Y相互独立知
[*]
故应选C．
[评注1] 本题考查二维离散型随机变量的概率计算．
[评注2] X与Y同分布时，不一定有X=Y或P{X=Y
| 一、填入单词，完成下面一段话。一空一词。 | ||||||
| Welcome 1________ the Science Center (科技中心). We 3________ an exhibition hall (展厅) and a movies show room 2________ the first floor. The exhibition 4________ is on 5________ left and the show room is on the 6________. On the 7________ floor, we have five 8________: the computer training (培训) area, the games area, the space technology (航天科技) area, the library and the biology specimen (生物标本) area. 9________ the gate, you can see the library on your 10________. The biology area is on your right. The computer training area is behind the library. The space technology area is behind the biology area. The games area is 11________ the training area 12________ the space area. It's 13________ the middle. You can see lots 14________ interesting documentaries in the movies show room. You can also enjoy the new Hi-tech (高科技) in the exhibition room. You can 15________ books in the big library. You can learn a lot 16________ computer in the training area. You can play interesting new 17________ You can see a space shuttle (宇宙飞船) in the space area. If you like 18________, you can see lots of specimen. Just come and have a wonderful day here! | ||||||
| 二、请认真阅读上面的文字，依照它绘制出科技中心的平面图，并且标明每个区域的名字。 | ||||||
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