【多选题】若由n个随机变量构造的统计量服从χ^2分布,则需满足下列哪些要求() A 随机变量X_1,X_2,......,X_n相互独立 B X_i(i=1,2......,n)服从标准正态分布N(0,1) C 随机变量的和 服从χ^2分布 D 随机变量的平方和 服从分布 E 自由度是n+1 F 自由度是n
A.
随机变量X_1,X_2,……,X_n相互独立
B.
X_i(i=1,2……,n)服从标准正态分布N(0,1)
【单选题】对柳永《八声甘州》词句解释不正确的一项是( )
A.
开头两句写雨后江天,澄澈如洗,一个“对”字就写出登临纵目、望尽天涯的境界
C.
“何事苦淹留”:不知道什么原因流连于此,不忍离去
【单选题】在Excel工作表中,正确表示if函数的表达式是( )。
【简答题】Suggestopaedia believes that language learning can occur at a much faster rate than it is often expected if learners can make better use of their______ powers.
【单选题】Risks associated with nuclear power ______.
A.
can only occur at the plant Site
B.
may occur when wastes are transported or recycled
C.
are limited to structural problems within the plant
D.
are primarily a result of carelessness
【单选题】随机变量X服从标准正态分布N(0,1).若【图片】取值为0.1,0.3,0.5,0.7,0.9,则对应的【图片】值分别是:
A.
-1.2816,-0.5244,0,0.5244,1.2816
B.
1.2816,0.5244,0,0.5244,1.2816
C.
1.2816,0.5244,0,-0.5244,-1.2816
D.
-7.2816,-0.5244,0,0.5244,7.2816
【单选题】在Excel工作表中,正确表示if函数的表达式是( )。
B.
IF(" 平均成绩">60,"及格","不及格")
【单选题】设随机变量X服从标准正态分布N(0,1),则E(X )=
【简答题】Suggestopaedia believes that language learning can occur at a much faster rate than it is often expected if learners can make better use of their______ powers.
【单选题】X服从正态分布N(4,25),下面哪个随机变量服从标准正态分布N(0,1)?