为啥要的时候用加减法 有的时候用乘法

问题如下：

An analyst studies historical data and finds that equities have had a geometric nominal return of 12%. Considering a real return of 2% for riskless Treasury bills and an annual inflation rate of 3%, the nearest estimates for the real rate of return and the equity risk premium are:

选项：

A.

8.7% and 6.6%

B.

8.7% and 8.2%.

C.

9.3% and 7.8%.

解释：

In this scenario, the nominal return is 12% and the inflation rate is 3%.

1+Real Return=(1+0.12)/(1+0.03)≈1.087

Hence, the real rate of return is approximately 8.7%.

1+Equity Risk Premium=(1+Real Return)/(1+Risk-Free Rate)=1.087/1.02=1.066

Expressed as a percentage, the equity risk premium is 6.6%.