A student has a weight of 534 N. The student sits in a chair. When the student sits in a chair, how much force does the chair apply to the student?

Explanation:

yes, according to the law of physics the force applied to the object the object also applies the same force to you. 534N is correct

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.