Suppose that treasury bills are currently paying 9 percent and the expected inflation rate is 3 percent. what is the real interest rate?

4Since the population is increasing, apply exponential growth: y= a (1+r)^t

The population starts at 1, therefore, a=1, and the population quadruples, "quad" means four, therefore, y=4. T=1, r= the rate of the population, you are trying to solve for r. 

Steps:

1. 4= 4(1+r)^1

2. Apply PEMDAS

3. 4=1(1+r)

4. 4= 1+r

5. Subtract the 1 on both sides. 

6. r=3

7. R = 3 or 300%.

Your answer is 300%.