R^2 等于 自变量方差/应变量方差？

问题如下：

John, an analyst ran a simple regression explaining the variation in electricity consumption as a function of temperature. The total variation of the dependent variable was 132.08, and the explained variation was 60.38. She had 60 monthly observations.

Calculate the coefficient of determination.

选项：

A.0.4571 B.2.19 C.0.21

解释：

The coefficient of determination is 0.4571:

$\frac{{{\rm{Explain variation}}}}{{{\rm{Total variation}}}} = \frac{{60.38}}{{132.08}} = 0.4571$