Listed here are product costs for production of soccer balls. Classify each cost as either direct or indirect. Product Cost Direct or Indirect 1. Needles used in stitching soccer balls 2. Wages of factory maintenance workers 3. Factory supervisor salary Direct 4. Wages of product assembly workers 5. Wages of factory machine operators 6. Coolants for machinery 7. Machinery depreciation (straight-line) 8. Annual flat fee paid for factory cleaning 9. Leather covers for soccer balls 10. Annual flat fee paid for factory security Indirect Direct Direct