National Express reports the following costs and expenses in June 2017 for its delivery service. Indirect materials $6,700 Drivers’ salaries $16,600 Depreciation on delivery equipment 11,700 Advertising 4,800 Dispatcher’s salary 5,410 Delivery equipment repairs 440 Property taxes on office building 970 Office supplies 680 CEO’s salary 12,300 Office utilities 1,000 Gas and oil for delivery trucks 2,600 Repairs on office equipment 220 Determine the total amount of (a) delivery service (product) costs and (b) period costs.