Answer:
4:3
Explanation:
Because there are 12 boys out of the 28 students in the class, there would have to be 16 girls in the class. This information would make the ratio 16:12. Although that is not the lowest you can go, so you would divide both numbers by the same value, to get both as low as possible, in this case, you would divide both by 4. Now your ratio is 4:3, which can also be said as, for every 4 girls in the class, there are 3 boys.