4. From the following selected accounts, compute the net working capital (10 pts):

Equity 4,000

Salaries expense 6,900

Rent Expense 2,000

Prepaid Insurance 3,000

Mortgage payable 8,000

Interest Payable 100

Interest Expense 100

Fuel expense 165

Delivery Truck 14,000

Buildingl 41,310

Contract revenue 13,690

Cash$21,000

Accounts Receivable 7,200

Accounts Payable 8,300