A principal $7000, rate 5%=0.05, and time 2 years is given.
It is stated that it is compounded semiannually, that is, twice in a year.
The question requires that you calculate the amount in the account after 2 years and the interest earned.
The formula for the amount (compound interest) is given as:
![A=P(1+(r)/(n))^(nt)](https://img.qammunity.org/2023/formulas/mathematics/high-school/39foo2gerf9tf1ffk32zwshrn339mz02kv.png)
Where,
• A is the final amount.
,
• P is the principal
,
• r is the rate
,
• n is the number of times interest is compounded annually.
,
• t is the time in years.
In this case P=7000, r=0.05, n=2, t=2. Substitute these values into the formula:
![\begin{gathered} A=7000(1+(0.05)/(2))^(2(2))=7000(1+0.025)^4 \\ =7000(1.025)^4\approx7000(1.103813) \\ \approx\$7,726.69 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/r8xu2y47kzx5zyljl6s6q7bkvemetu5cw1.png)
The equation that relates the amount, A, principal, P, and interest earned, I is given as:
![A=P+I](https://img.qammunity.org/2023/formulas/mathematics/high-school/8g89j5m2go6x0rj4uddg8hts081d3jw09p.png)
Substitute A=7,726.69, P=7000 into the formula:
![\begin{gathered} 7,726.69=7,000+I \\ \Rightarrow I=7,726.69-7,000=\$726.69 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/m597vqzk1v8ych3m5nlrqt7l44y9s2f1zc.png)
It follows that:
The amount of money in the account after 2 years is about $7,726.69.
The amount of interest earned is about $726.69.