A high school physics student is sitting in a seat reading this question. The magnitude of the force with which the seat is pushing up on the student to support him is closest to what?

Question

unklerhaukus · Answer

The Force pushing down is the force of Gravity. On a chair It is in perfect balance with the force pushing up (the normal force). 
 
in terms of magnitude $$F _{N} = F _{G} = mg$$ 
where m is the students mass in kg 
and g is acceleration due to gravity ~9.8ms^-2

the forces are in opposite directions