Question 1167713
The equation for an ellipse centered at the origin is x^2/a^2 + y^2/b^2 = 1, where a, b are the semi-major and semi-minor axes, respectively. 
The sun is located at one focus with coordinates (-c,0), with c^2 = a^2 - b^2. 
For simplicity, we will express the distances in billions of miles. 
The distance of the furthest approach is 7.4 = c + a, and the closest 
approach is 4.4 = a - c. Solving for a gives 2a = 11.8 -> a = 5.9.  
Solving for c gives 2c = 3 -> c = 1.5.
b^2 = a^2 - c^2 -> b^2 = 5.9^2 - 1.5^2 = 32.56.
Thus, the equation is x^2/34.81 + y^2/32.56 = 1.
If another planet is placed at the other focus, the distance between them 
will be 2c = 3.