因为D的左侧累计值最大吗？

问题如下：

The following graphs show the cumulative distribution function (CDF) of four different random variables. The dotted vertical line indicates the mean of the distribution. Assuming each random variable can only be values between -10 and 10, which distribution has the highest variance?

选项：

A.

B.

C.

D.

解释：

Varianceis a measure of the mean deviation. In the above four graphs, it can be seenthat D has the highest proportion of the distribution that deviates from themean, and it also has a relatively higher density in both tails. Hence, D hasthe highest variance.