I take great offense at your

你的概括让我很生气

- Where is your right? - I have every right.

-你无权这么说 -我有任何权利

divided by m1 + m2 + m3.

除以 m1 + m2 + m3

where the index I will go over a range from 1 to 3.

下标 i 会从 1 取到 3

P_Y and allocations X^,

X^ Y^和I的分配

the I's of X^ equals the summation for all the I's of e^_x.

所有的在I 中的E^到X的总和

it is the same R^2 for everybody.

对每一小块来说 R^2 相同

and you just get M·R^2.

就得到 M·R^2

and that's really--you see it's the same thing

其实这两个式子是一样的

Those are the two population definitions.

这是两种对总体的定义

because there's going to be a d dot ri twice.

因为这里有两倍的 d 点乘 ri

It's common to all the terms in the sum and you pull it out.

它对所有项来说都是常量 可以提出来