Answer :
In order to calculate the final amount of money, let's use the following formula:
[tex]P=P_0(1+\frac{i}{n})^{nt}[/tex]Where P is the final value after t years, P0 is the initial value, i is the annual interest and n depends on the compound period (for monthly, we have n = 12).
Using P0 = 800, i = 0.025, t = 3 and n = 12, we have that:
[tex]\begin{gathered} P=800(1+\frac{0.025}{12})^{12\cdot3} \\ P=800\cdot1.0778 \\ P=862.24 \end{gathered}[/tex]So the amount of money after 3 years is $862.24.