Consider the attached ellipse. Let the sun be at the right focus. Then perihelion is at right vertex on the x-axis and aphelion is at the left vertex on the x-axis.
The distances:
- from perihelion to the sun in terms of ellipse is a-c;
- from aphelion to the sun in terms of ellipse is a+c.
Then

Add these two equations:
and subtract first equation from the second:
Note that
thus

The equation for the planet's orbit is

The answer to the question
Answer:
the ratio of make to female teachers is 3:7