Answer: 55% of the seats in the theater were filled by the 6th graders on the trip.
Explanation:
Given: Total seats = 3100
Seats vacant= 1395
Seats occupied by 6th graders = 3100-1395 = 1705
The percentage of the seats in the theater were filled by the 6th graders on the trip =


Hence, 55% of the seats in the theater were filled by the 6th graders on the trip.