Question
When Martin was born, his father set up a $5,000 college fund for him with an annual compound interest rate of 7.3%. What is the total value of this account after 18 years, and what was the interest earned on the account? Round the answers to two decimal places. *Remember to use your STAAR Reference Sheet for support! (2 points) The final amount of the college fund is $ , and the amount of interest earned on the account is $
Answers
GPT-4o mini
To calculate the total value of Martin's college fund after 18 years with an initial deposit of $5,000 and an annual compound interest rate of 7.3%, we can use the formula for compound interest:
\[
A = P(1 + r)^n
\]
Where:
- \( A \) = the amount of money accumulated after n years, including interest.
- \( P \) = the principal amount (the initial amount of money).
- \( r \) = annual interest rate (decimal).
- \( n \) = the number of years the money is invested or borrowed.
In this case:
- \( P = 5000 \)
- \( r = 7.3\% = 0.073 \)
- \( n = 18 \)
Now, substituting the values into the formula:
\[
A = 5000(1 + 0.073)^{18}
\]
Calculating:
\[
A = 5000(1.073)^{18}
\]
First, calculate \( (1.073)^{18} \):
\[
(1.073)^{18} \approx 3.566
\]
Now, multiply by the principal amount:
\[
A \approx 5000 \times 3.566 \approx 17830.00
\]
Thus, the total value of the college fund after 18 years is approximately **$17,830.00**.
Next, to find the interest earned, subtract the principal from the total amount:
\[
\text{Interest} = A - P = 17830.00 - 5000 = 12830.00
\]
So the amount of interest earned on the account is approximately **$12,830.00**.
Putting it all together:
- The final amount of the college fund is **$17,830.00**.
- The amount of interest earned on the account is **$12,830.00**.
\[
A = P(1 + r)^n
\]
Where:
- \( A \) = the amount of money accumulated after n years, including interest.
- \( P \) = the principal amount (the initial amount of money).
- \( r \) = annual interest rate (decimal).
- \( n \) = the number of years the money is invested or borrowed.
In this case:
- \( P = 5000 \)
- \( r = 7.3\% = 0.073 \)
- \( n = 18 \)
Now, substituting the values into the formula:
\[
A = 5000(1 + 0.073)^{18}
\]
Calculating:
\[
A = 5000(1.073)^{18}
\]
First, calculate \( (1.073)^{18} \):
\[
(1.073)^{18} \approx 3.566
\]
Now, multiply by the principal amount:
\[
A \approx 5000 \times 3.566 \approx 17830.00
\]
Thus, the total value of the college fund after 18 years is approximately **$17,830.00**.
Next, to find the interest earned, subtract the principal from the total amount:
\[
\text{Interest} = A - P = 17830.00 - 5000 = 12830.00
\]
So the amount of interest earned on the account is approximately **$12,830.00**.
Putting it all together:
- The final amount of the college fund is **$17,830.00**.
- The amount of interest earned on the account is **$12,830.00**.