The magnitude of the net electrical force acting on the +6 µc charge, rounded to the tenths place, is n.

Electrical force is the repulsive or attractive force of attraction between any two charged bodies. it is possible to calculate electric force on anything that runs on batteries or uses a plug. Its net effect can be explained using newtons law of motion like any force.
 From the coulombs law; F = k (q1║q2)/ r²
                       Where k = 9 ×10∧9 N.m².C∧-2, r12= 0.285m, q2= +6μC and q1 = 4.86 nC
substituting values in the equation
 the net electrical force acting on the +6ц C charge is 5.4 N.