Net force problem pretty simple

[jayced]

When on the ground, Ian's weight is measured to be 646 N. When Ian is on an elevator, his apparent weight is 711 N. What is the net force on the system (Ian and the elevator) if their combined mass is 1050 kg?

I know that Fnet is the sum of all forces. I don't have any examples of this problem so I just summed that Fnet=646N+711N+(1050kg x 9.8m/s)

Am I on the right track at all?

Should I be using another equation?

Thanx

 

[rl.bhat]

Apparent weight in an accelerating lift is given by
Wapp = n(g + or - a), where a is the acceleration do the lift.
From the given values find the acceleration of the lift. From that find the net force on the system.