Answer
$34,972.98
Step-by-step explanation:
The amount after 4 years can be calculated as:
![A=P(1+r)^n](https://img.qammunity.org/2023/formulas/mathematics/college/epztmgvpne07k8kwtk27qc0yl8i81wulbo.png)
Where P is the initial investment, r is the interest rate and n is the number of years. So, replacing P = $21,000, r = 13.6% = 0.136 and n = 4, we get:
![\begin{gathered} A=21,000(1+0.136)^4 \\ A=34,972.98 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/9pejfn7ly86k9xl0ec0b891dgymlgcmjrd.png)
Therefore, the answer is $34,972.98