NO.PZ2015120604000063
问题如下：
According to the above table, what is the covariance of X and Y?
选项：
A.0.72.
B.-4.8.
C.-0.72.
解释：
B is correct
Cov(X,Y) = 0.2(-2-1)(5-1.6) + 0.6(1-1)(2-1.6) +0.2(4-1) (-3-1.6) = -4.8
No.PZ2015120604000063 (选择题)
来源: 品职出题
According to the above table, what is the covariance of X and Y?
您的回答, 正确答案是: B
A
0.72.
B
-4.8.
C
不正确-0.72.
数据统计(全部)
做对次数: 5089
做错次数: 1851
正确率: 73.33%
数据统计(个人)
做对次数: 0
做错次数: 1
正确率: 0.00%
解析
B is correct
Cov(X,Y) = 0.2(-2-1)(5-1.6) + 0.6(1-1)(2-1.6) +0.2(4-1) (-3-1.6) = -4.8
