Answer:
160
Step-by-step explanation:
The fraction of students in grade 8 is ...
(grade 8 students)/(total students in all grades)
= 3.2/(3 +3.4 +3.2) = 3.2/9.6 = 1/3
Then the number of students in grade 8 is ...
(1/3)(480 students) = 160 students . . . in grade 8