股票的协方差如何计算？

协方差（Covariance）在概率论和统计学中用于衡量两个变量的总体误差。若两个随机变量X和Y相互独立，则E[(X-E(X))(Y-E(Y))]=0，因而若上述数学期望不为零，则X和Y必不是相互...

协方差（Covariance）在概率论和统计学中用于衡量两个变量的总体误差。若两个随机变量X和Y相互独立，则E[(X-E(X))(Y-E(Y))]=0，因而若上述数学期望不为零，则X和Y必不是相互独立的，亦即它们之间存在着一定的关系。

Cov(X，Y)=Cov(Y，X)；Cov(aX，bY)=abCov(X，Y)，（a，b是常数）；Cov(X1+X2，Y)=Cov(X1，Y)+Cov(X2，Y)。

MCSE boot camps have its supporters and its detractors. Some people do not understand why you should have to spend money on boot camp when you can get the MCSE study materials yourself at a fraction of the camp price. However, who has the willpower to actually sit through a self-imposed MCSE training.

MCSE boot camps have its supporters and its detractors. Some people do not understand why you should have to spend money on boot camp when you can get the MCSE study materials yourself at a fraction of the camp price. However, who has the willpower.

MCSE boot camps have its supporters and its detractors. Some people do not understand why you should have to spend money on boot camp when you can get the MCSE study materials yourself at a fraction of the camp price. However, who has the willpower.