Three-point charges are arranged along the x-axis. Negative Charge q1= -4.5 nC is located at x = +0.2 m, and positive charge q2 = +2.5 nC is at x = -0.3 m. A positive point charge q3 is located at the origin. i. Find the net electric field at the origin.

ii. What must the value of q3be for the net force on this point charge to have a magnitude of 4 μN?
iii. What is the direction of the total or net force on q3?