The box on the top left would be filled with -2x³; top right would be filled with 5x²; second left would be filled with 6x²; second right would be filled with -15x; bottom left would be filled with -8x; and bottom right would be filled with 20.
The classes could each have proportions of 5 boys to 6 girls, but they don’t necessarily have to be exactly 5 to 6. The number could 5 to 6 for one class, but it could also be 10 to 12 for another class, since 10 to 12 is a scale factor of 5 to 6.