Given:
Principal amount, P = 9,000
Time, T = 4 years
Interest rate, R = 2%
This is a simple interest problem.
To find the amount of Money Marsha earned in interest, apply the Sinple Interest formula:
![\text{Interest = }(P\ast R\ast T)/(100)](https://img.qammunity.org/2023/formulas/mathematics/college/ck2k6x47oyq4jwuwmmsn6pd1s0rq568hdf.png)
Thus, we have:
![\begin{gathered} \text{Interest = }(9000\ast2\ast4)/(100) \\ \\ \text{Interest = }(72000)/(100)=720 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/5j8g1iioapy7opqlhjbsnjmlze18dd4jak.png)
The amount Marsha did earn in interest is 720
To find her new account balance, apply the formula:
![A=\text{ Principal + Interest}](https://img.qammunity.org/2023/formulas/mathematics/college/f3nkba682t6war4vam2hm6k673gtbugpgt.png)
Thus, we have:
![\begin{gathered} A=9000+720 \\ \\ A=9720 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/f8sxjm9rcjlvw16e1drrq29md6igr4bmh4.png)
Therefore, her new account balance will be 9,720
ANSWER:
Interest = 720
New account balance = 9,720