Answer:
The force applied by fourth girl in east team is 220 N.
Explanation.
If neither side is wining, it means that force applied on both sides are equal.
Total force by team west = 250 N * 4 = 1000 N
Total force of 3 girls on east side = 260 N * 3 = 780 N
As we know the east team apply total force of 1000 N.
Force applied by the fourth girl in east team = 1000 N - 780 N = 220 N