What your friend was trying to do was to add the 250 N force to the x and y forces by components. That is to say if we break the 250 N force into x and y components we get
In the x direction: 160 N + 250*0.96 = 400 N
In the y direction: 370 N - 250*0.28 = 300 N
Unfortunately he/she didn't add them correctly and got the wrong components.
To finish the problem from here we are looking for a vector R such that x + y + R = 0. (Note carefully what direction R is in!)
As far as the angle 97.1, the angle the 250 N force is pointed in is acs(0.96) = 16.26 degrees below the x axis. So that number is wrong. (That may be why he/she got the components wrong.)
-Dan