schedule of machinery owned by Mazen Co. is presented below: Estimated Estimated Total Cost Salvage Value Life in Years Machine X $500,000 $50,000 14 Machine Y 800,000 80,000 10 Machine Z 300,000 60,000 Mazen computes depreciation by the composite method. The composite rate of depreciation (in percent) for these assets is 6 20. 21. The composite life (in years) for these assets is