Cheyenne, Inc. is considering purchasing equipment costing $66000 with a 6-year useful life. The equipment will provide annual cost savings of $16054 and will be depreciated straight-line over its useful life with no salvage value. Cheyenne requires a 10% rate of return. Present Value of an Annuity of 1 Period 8% 6 9% 4.623 4.486 4.355 10% 11% 12% 4.231 4.111 3.784 15% What is the approximate internal rate of return for this investment? 12% 10% 11% 9%