Problem: When $Y (> 0)$ has mean and variance equal to $\mu$ and $\mu/n$ respectively, it is shown in the textbook that the appropriate transformation of Y to stabilize variance is the square root transformation. Suppose that Y has mean equal to respectively, it is shown on pages 76-77 of our textbook that the mu and variance equal to $\frac{\mu^4}{n}$ where $n$ is "large". Find the appropriate transformation $Z = f(Y)$ of $Y$ that makes the variance of $Z$ equal to 1.
My feedback: I know I am to use the equation $Var(f(Y)) \approx [f'E(Y))]^2 \times Var(Y)$.
This is equivalent to $1 \approx [f'(\mu)]^2 \times (\frac{\mu^4}{n} )$.
I am struggling to understand how to apply this derivative to solve this equation.