Hi, I am currently studying for something due tomorrow and I am looking for an explanation for this. I need a detail explanation please.

Determinant of Interest Rates

The real risk- free rate of interest Is 4%. Inflation is expected to be 2% this year and 4% in during the next 2 years. Assume that the maturity risk premium is zero. What is the yield on 2 year Treasury securities? What is the yield on 3 year Treasury securities.

So I already have the working I just have a question about the working. I will provide the working below.

IP= 2%+4%= 6% / 2 = 3

R* + IP = 4% + 3%= 7%

(2% + 4% + 4%)/3 = 3.33%

r* + IP = 4 + 3.33 = 7.33%

My question is why did we find the 7 percent in the first place and where did we get the extra 4% to solve for 3.33%

I am sort of confused and I would like some explaining in detail please <3