This is how it's suppose to be hooked up:
On the right side, the cable jacket is held with a little bracket/screw (which you are missing), then the end of the cable fits into a hole on the arm.
You have a different end on the throttle cable, plus you are missing the bracket to hold the cable, so you are going to have to rig something up.
You just need something to hold the outside of the cable from moving, and then attach it to the arm: