Answer
$\frac{x^2}{4}+\frac{y^2}{8}=1$
Work Step by Step
Step 1. Based on the given conditions, we have $c=2, b=2$; thus $a^2=b^2+c^2=8$.
The ellipse is centered at $(0,0)$ with a vertical major axis.
Step 2. We can write the equation as $\frac{x^2}{4}+\frac{y^2}{8}=1$
