Compound interest:
[tex]A=P\left(1+\dfrac rn\right)^{nt}[/tex]
where [tex]P[/tex] is the amount you start with, [tex]r[/tex] is the interest rate, [tex]n[/tex] is the number of times interest is compounded per year, and [tex]t[/tex] is amount of time that passes.
[tex]4272\left(1+\dfrac{0.12}1\right)^{1\times3}=4272\times1.12^3\approx6001.85[/tex]