Answer:
if the annual interest rate is 7%, then you need to invest:
present value = future value / (1 + i)ⁿ
- future value = $2,200,000
- i = 7%
- n = 28 years
present value = $2,200,000 / (1 + 7%)²⁸ = $330,884.87
if the interest rate is 15%, the you need to deposit a smaller amount:
present value = future value / (1 + i)ⁿ
- future value = $2,200,000
- i = 15%
- n = 28 years
present value = $2,200,000 / (1 + 15%)²⁸ = $43,942.34