What is the value of the objective function at the optimal solution? (Answer in dollars)

Please do not say 3150, this is not the correct answer

9. Eric Brown is responsible for upgrading the wireless network for his employer. He has identified seven possible locations to install new nodes for the network. Each node can provide service to different regions within his employer's corporate cam- pus. The cost of installing each node and the regions that can be served by each node are summarized below. Node 1: Regions 1, 2,5; Cost: $700 Node 2: Regions 3, 6, 7, Cost $600 Node 3: Regions 2,3,7,9; Cost $900 Node 4: Regions 1, 3, 6, 10; Cost $1,250 Node 5: Regions 2,4,6,8; Cost $850 Node 6: Regions 4,5, 8, 10; Cost $1,000 Node 7: Regions 1,5,7,8,9; Cost $100