Answer
$\frac{x^{2}}{25}+\frac{y^{2}}{16}=1$
Work Step by Step
The major axis is along the x-axis. Therefore, the equation of the ellipse is of the form
$\frac{x^{2}}{a^{2}}+\frac{y^{2}}{b^{2}}=1$ where a is the semi-major axis and b is the semi-minor axis.
From the graph, we find that a=5 and b=4.
Therefore, the equation of the ellipse is
$\frac{x^{2}}{25}+\frac{y^{2}}{16}=1$
