L9 Homework
Score: 45.12/87
Answered: 8/19

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Question 3

If 7000 dollars is invested in a bank account at an interest rate of 4 percent per year:

A. Find the amount in the bank after 11 years if interest is compounded annually.
B. Find the amount in the bank after 11 years if interest is compounded quarterly.
C. Find the amount in the bank after 11 years if interest is compounded monthly.

Round all answers to 2 decimal places.

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Answer :

Sure, let's break down the solution for each part of the question step-by-step.

### Problem:
You invested [tex]$7000 in a bank account with an annual interest rate of 4%. You need to find the amount in the account after 11 years with different compounding periods: annually, quarterly, and monthly. ### Given: - Principal amount (P): $[/tex]7000
- Annual interest rate (r): 4% or 0.04
- Time (t): 11 years

Let’s consider each case one by one.

### 1. Compounded Annually:
With annual compounding, interest is added once per year.

The formula for the compounded amount is:
[tex]\[ A = P \left(1 + \frac{r}{n}\right)^{nt} \][/tex]

Since interest is compounded annually:
- [tex]\( n = 1 \)[/tex]

So, the formula simplifies to:
[tex]\[ A_{\text{annually}} = P \left(1 + r\right)^t \][/tex]

Plugging in the values:
[tex]\[ A_{\text{annually}} = 7000 \left(1 + 0.04\right)^{11} \][/tex]

After calculating, we get:
[tex]\[ A_{\text{annually}} = \$10776.18 \][/tex]

### 2. Compounded Quarterly:
With quarterly compounding, interest is added 4 times per year.

The formula remains the same, but with:
- [tex]\( n = 4 \)[/tex]

So:
[tex]\[ A_{\text{quarterly}} = P \left(1 + \frac{r}{4}\right)^{4t} \][/tex]

Plugging in the values:
[tex]\[ A_{\text{quarterly}} = 7000 \left(1 + \frac{0.04}{4}\right)^{4 \cdot 11} \][/tex]

After calculating, we get:
[tex]\[ A_{\text{quarterly}} = \$10845.22 \][/tex]

### 3. Compounded Monthly:
With monthly compounding, interest is added 12 times per year.

The formula remains the same, but with:
- [tex]\( n = 12 \)[/tex]

So:
[tex]\[ A_{\text{monthly}} = P \left(1 + \frac{r}{12}\right)^{12t} \][/tex]

Plugging in the values:
[tex]\[ A_{\text{monthly}} = 7000 \left(1 + \frac{0.04}{12}\right)^{12 \cdot 11} \][/tex]

After calculating, we get:
[tex]\[ A_{\text{monthly}} = \$10861.00 \][/tex]

### Summary:
- Amount after 11 years with annual compounding: \[tex]$10776.18 - Amount after 11 years with quarterly compounding: \$[/tex]10845.22
- Amount after 11 years with monthly compounding: \$10861.00

Make sure to double-check your calculations if you do it by hand or using a calculator to ensure accuracy.