Me plz i really need your any one 20 points

The first proposal identifies total costs for materials and labor. The proposed charges add to ...
  410.20 +919.60 +9675.00 = 11,004.80
When divided by the number of seats (4250), the per-seat amount is computed to be
  $11,004.80/(4250 seats) ≈ $2.5894/seat

The second proposal breaks out charges on a per-seat basis, so those can be added directly to give a per-seat total.
  ($0.35 +0.75 +1.50)/seat = $2.60/seat

The second proposal is about $2.60 -2.5894 = 1.06 ¢/seat more than the first.

It should be c i think.