Final answer:
The after-tax real rate of interest is 1.5%.
Step-by-step explanation:
The after-tax real rate of interest can be found by subtracting the effect of taxes and inflation from the nominal rate.
In this case, the nominal rate is 4 percent, inflation is 2 percent, and the marginal tax rate is 25 percent.
To calculate the after-tax real rate of interest, first subtract the inflation rate from the nominal rate
(4% - 2% = 2%).
Then, multiply this result by (1 - tax rate) to account for taxes
(2% * (1 - 0.25) = 1.5%).
Therefore, the after-tax real rate of interest is 1.5%.