Given:
Amount = $9000
Rate=5.5%
time =21
Formula:
[tex]A(t)=P(1+\frac{r}{n})^{nt}[/tex]
Where,
[tex]\begin{gathered} p=9000 \\ r=\frac{5.5}{100} \\ r=0.055 \\ n=12 \\ t=21 \end{gathered}[/tex]
[tex]\begin{gathered} A(t)=P(1+\frac{r}{n})^{nt} \\ A(21)=9000(1+\frac{0.055}{12})^{12\times21} \\ A(21)=9000(1.00458)^{12\times21} \\ A(21)=9000(1.00458)^{252} \\ A(21)=9000\times3.165658 \\ A(21)=28490.92 \end{gathered}[/tex]
so amount after 21 year is $28490.92
