If the ratio of boys to girls in the class is 4:3, that means for every 4 boys there are 3 girls.
Also, in average for each group of 7 students, there are 4 boys and 3 girls, so the ratio of boys to the number of students is 4:7 and the ratio of the number of students to the number of girls is 7:3.
So the correct options that states these relations are A, C and E.