问题如下：
Calculate the expected return that an equal-weighted investment in the three securities could provide.
选项：
解释：
Risk free interest rate (nominal) (%)+Premiums(%)=Expected annual fixed-income return (%)
Estimate of the expected return of an equal-weighted investment in the three securities: (3.8% + 4.8% + 6.1%)/3 = 4.9%.
解析：首先，我们先计算出每种债券各自的收益。
1-year government bond没有任何风险溢价，所以它的收益率就是3.8%
相比较于1-year government bond，10-year government bond存在期限溢价，因此它的收益是：3.8%+1%=4.8%
相比较于1-year government bond，10-year corporate bond存在期限溢价，信用溢价以及流动性溢价，因此它的收益是3.8% +1% + 0.75% + 0.55%=6.1%
又因为这三类债券投资权重相等，所以直接求算数平均就可以求得投资的回报，即
(3.8% + 4.8% + 6.1%)/3 = 4.9%.
She will only make the added investment provided that the expected spread/premium of the equally weighted investment is at least 1.5 percent (150bp) over the 1-year government bond.
题干中的这句话是什么意思呢?
