To find the present value (PV) of the payment stream from the money machine that pays $1,000.00 per year for 30 years starting 5 years from today, we will break the problem into two parts.
- Calculate the present value of the annuity (payments) at the time the annuity starts (after 5 years).
- Discount that total back to today.
Step 1: Present Value of the Annuity at Year 5
We need to calculate the present value of an annuity that pays $1,000 per year for 30 years at a discount rate of 7%. The formula for the present value of an ordinary annuity is:
\[ PV = P \times \left(1 - (1 + r)^{-n}\right) / r \]
where:
- \( P \) = payment per period ($1,000)
- \( r \) = interest rate (0.07)
- \( n \) = number of payments (30)
Plugging in the values:
\[ PV = 1000 \times \left(1 - (1 + 0.07)^{-30}\right) / 0.07 \]
Calculating \( (1 + 0.07)^{-30} \):
\[ (1 + 0.07)^{-30} ≈ (1.07)^{-30} ≈ 0.131366 \]
Now substitute this value back into the annuity formula:
\[ PV = 1000 \times \left(1 - 0.131366\right) / 0.07 \]
\[ PV = 1000 \times 0.868634 / 0.07 \]
\[ PV ≈ 1000 \times 12.40906 \]
\[ PV ≈ 12409.06 \]
This is the present value of the annuity at time 5 years from today.
Step 2: Discounting the Present Value Back to Today
Now we need to discount this amount back to today (3 years before the annuity starts, since it starts in 5 years).
Using the present value formula:
\[ PV = FV / (1 + r)^n \]
Where:
- \( FV \) = future value which we calculated as \( 12409.06 \)
- \( r \) = interest rate (0.07)
- \( n \) = number of years until the first payment (5)
So, we calculate:
\[ PV = 12409.06 / (1 + 0.07)^5 \]
Calculating \( (1 + 0.07)^5 \):
\[ (1 + 0.07)^5 ≈ 1.402552 \]
Now substitute this back into the PV formula:
\[ PV ≈ 12409.06 / 1.402552 \]
\[ PV ≈ 8843.55 \]
Final Result
The value today of the money machine that will pay $1,000.00 per year for 30 years, starting in 5 years, at an interest rate of 7% is approximately:
\[ \text{$8,843.55} \]