standard_description: Write arithmetic and geometric sequences both recursively and with an explicit formula, use them to model situations, and translate between the two forms.
problem_activity: Task
There are 270 students at Colfax Middle School, where the ratio of
boys to girls is 5:4. There are 180 students at Winthrop Middle
School, where the ratio of boys to girls is 4:5. The two schools
hold a dance and all students from both schools attend.  What
fraction of the students at the dance are girls?


aligns: no