Use the compound interest formula:
[tex]A=P(1+\frac{r}{n})^{nt}[/tex]Where:
A = Final amount including principal
P = Principal amount = 2100
r = interest rate = 5.4% = 0.054
t = time = 3.5
n = number of times interest is compounded = 365
[tex]\begin{gathered} A=2100(1+\frac{0.054}{365})^{365\cdot3.5} \\ A=2100(1.208024065) \\ A=2536.850536 \end{gathered}[/tex]