Numerical Methods: Euler to Runge–Kutta · Hard problem

For $y' = y$, $y(0) = 1$, Euler's method gives $y(1) \approx 2.25$ with $h = \dfrac{1}{2}$ and $y(1) \approx 2.44140625$ with $h = \dfrac{1}{4}$. Since Euler's error is approximately $Ch$, combine the two values by Richardson extrapolation to get an improved estimate of $y(1)$. Round to four decimal places.