In this case the formula of an ellipse is
[tex]\frac{x^2}{a^2}+\frac{y^2}{b^2}=1[/tex]
In our case a helps to the wise and b with the tall
[tex]a=\sqrt[]{400}=20[/tex][tex]b=\sqrt[]{144}=12[/tex]
Then if we need twice the wide
[tex]2a=2(20)=40[/tex]
and 1.5 the tall
[tex]1.5(12)=18[/tex]
Therefore our new equation is
[tex]\frac{x^{2}}{1600}+\frac{y^{2}}{324}=1[/tex]
ANSWER
[tex]D\text{. }\frac{x^{2}}{1600}+\frac{y^{2}}{324}=1[/tex]
