at between 7% and 13% =处在7%到13%之间

(1)at  prep.以，达（某一速度、频率、水平或价格）(英文解释 You use at to express a rate, frequency, level, or price.）

I drove back down the highway at normal speed.  

我以正常车速沿公路返回。

Check the oil at regular intervals, and have the car serviced regularly. 定期检查汽油，并对车辆进行定期维护。

(2)at prep.以，达（某一数量）

Weighing in at eighty tons, the B-19 was easily the largest and most sophisticated warplane in the world.  

B-19重达80吨，无疑是世界上最大、最先进的军用飞机。

as unemployment stays pegged at three million.  

当失业人数维持在300万

英文句子全面解析如下

He(主语) calculates(谓语) the return on investment in high-quality birth-to-five education(宾语) at between 7% and 13%(状语).

参考译文：他计算出从高质量的出生到5岁教育的投资回报率在7%到13%之间。

重点单词及短语解析如下:

(1)calculate vt.计算，估算;估计

From this you can calculate the total mass in the Galaxy.

由此你可以算出银河系的总质量。

(2)the return n.利润;回报;收益

Profits have picked up this year but the return on capital remains tiny.

今年的利润已经回升，但是资本收益仍然很少。

Higher returns and higher risk usually go hand in hand.  

更高的收益通常伴随着更高的风险。

(3)investment n.  投资，投资额; （时间、金钱精力的）投入

He said the government must introduce tax incentives to encourage investment. 

他说政府必须推出税收激励政策来鼓励投资。

Investment could dry up and that could cause the economy to falter.  

投资可能会中断，而这会引起经济衰退。

(4)on investment 投资

The success of the project pivots on investment from abroad.  

这个工程的成功主要依靠外来投资.

You'll be able to earn an average rate of return of 8% on your investments.  

你将能获得 8% 的平均投资收益率。

(5)the return on investment 投资报酬率，投资回报率，投资收益率

The return on investment required by the chief executive will influence the operation of managers'targets.  

行长所要求的投资收益会对执行经理的目标实施产生影响.

Managing and measuring the return on investment of marketing programs. 管理并衡量行销活动之投资报酬率.

(6)high-quality birth-to-five education 高质量的出生到5岁教育

(7)between 7% and 13% 在7%到13%之间