Need help with Questions 3 and 4, answer for previous question for Question 3 is +160 going to the right

Question 3 1 pts For the previous question, find the electric field (in newtons/coulomb) at the position of the test charge. Again, supply a positive value if the electric field points to the right and a negative value if it points to the left. Do not include units with your answer. Question 4 0.5 pts A fixed system of charges exerts a force of magnitude 21 N on a 7.0 C charge. The 7.0 C charge is replaced with a 4.0 C charge. What is the exact magnitude of the force (in N) exerted by the system of charges on the 4.0 C charge? Do not include units with your answer.2.110 g 311C 3cm 20111 The gure shows a test charge q between the two positive charges. Find the force (in newtons} on the test charge for q = 4 |.1C. Give a positive answer if the force is to the right and a negative answer if the force is to the left