Numerical Methods: Euler to Runge–Kutta · Medium problem

A savings balance grows according to $A' = 0.03A$ (continuous $3\%$ annual interest), $A(0) = 800$. Using one step of the classical RK4 method with $h = 1$ year, estimate the balance after one year, and find the estimated interest earned that year (balance after one year minus the initial $800). Round to the nearest cent.