Three Children standing on a raft:Engineering Mechanics

[Dfresh]

Homework Statement

Three Children are standing on a raft 5x5m. If the weights of the children at Points A,B,and C is 375N,260N,and400N, respectively, determine the magnitude and the point of application of the resultant of the three weights
Link to diagram:
http://www.chegg.com/homework-help/three-children-standing-5-x-5-m-raft-weights-children-points-chapter-3-problem-127p-solution-9780077275563-exc

Homework Equations

Sum of forces?

The Attempt at a Solution

So basically for this question, I'm stuck on the point of application part. The magnitude was easy enough, I just added all the forces. I'm not really sure how to approach the point of application part.

 

[Simon Bridge]

The idea is to replace the three forces with an equivalent single force - one that has the same effect.

 

[rude man]

Think of it like this: Pretend the resultant force lifts the raft above the surface of the water. At the resultant point the raft must not tip in any direction.