Answer
$34,972.98
Explanation:
The amount after 4 years can be calculated as:
[tex]A=P(1+r)^n[/tex]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:
[tex]\begin{gathered} A=21,000(1+0.136)^4 \\ A=34,972.98 \end{gathered}[/tex]Therefore, the answer is $34,972.98