A positive covariance means that the two move together.

一个正值的协方差表示两个变量同向变动

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If they tend to move together, when x is high and y is high together at the same time, then the covariance will tend to be a positive number.

如果x和y同向变动,当x值和y值同时都很大,协方差的结果将会是一个正值

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