Answer
Answer may vary.
$Y_{min}=4, Y_{max}=12, Y_{scl}=1$.
Work Step by Step
Answer may vary.
Based on the given data, we can find the range in X-direction $\Delta X=X_{max}-X_{min}=8-(-4)=12$.
For the viewing rectangle to be a square screen, we need the range in Y-direction $\Delta Y=\frac{2}{3}\Delta X=8$.
To contain point $(4,8)$, we can choose $Y_{min}=4, Y_{max}=12, Y_{scl}=1$.