Savings Annuity Ba6E9D
1. **Problem statement:** You deposit 750 each month into a savings annuity at an annual interest rate of 3.5%. We want to find:
a. The amount in the account after 25 years.
b. The total money deposited.
c. The total interest earned.
2. **Formula for future value of an ordinary annuity:**
$$A = P \times \frac{(1 + r)^n - 1}{r}$$
where:
- $A$ is the amount in the account after $n$ periods,
- $P$ is the monthly deposit,
- $r$ is the monthly interest rate (annual rate divided by 12),
- $n$ is the total number of deposits (months).
3. **Calculate parameters:**
- Annual interest rate = 3.5% = 0.035
- Monthly interest rate $r = \frac{0.035}{12} = 0.0029167$
- Number of months $n = 25 \times 12 = 300$
- Monthly deposit $P = 750$
4. **Calculate future value $A$:**
$$A = 750 \times \frac{(1 + 0.0029167)^{300} - 1}{0.0029167}$$
Calculate $(1 + 0.0029167)^{300}$:
$$ (1.0029167)^{300} \approx 2.34935 $$
So,
$$A = 750 \times \frac{2.34935 - 1}{0.0029167} = 750 \times \frac{1.34935}{0.0029167} \approx 750 \times 462.63 = 346972.5$$
5. **Total money deposited:**
$$\text{Total deposits} = P \times n = 750 \times 300 = 225000$$
6. **Total interest earned:**
$$\text{Interest} = A - \text{Total deposits} = 346972.5 - 225000 = 121972.5$$
**Final answers:**
- a. Amount in account after 25 years: $346972.5$
- b. Total money deposited: $225000$
- c. Total interest earned: $121972.5$