请问Residual divdend是什么概念？在讲义中的哪个知识点有提到计算？

问题如下：

The Apex Corp. has a target debt/equity ratio of 40/60. Its capital budget for next year is estimated to be $40 million. Estimated net income is $30 million. If Apex follows a residual dividend policy, its dividend is expected to be:

选项：

$6 million.

$12 million.

$18 million.

解释：

A is correct.

Using the residual dividend policy, with a target debt/equity ratio of 40/60, 60 percent or $24 million of the $40 million in capital expenditures will be financed with equity; $30 million net income – $24 million retained earnings = $6 million for dividends.