internal rate of return method help please 409431

can someone help me how to do this please? ..I am not good at all with accounting.

All Star, Inc., is considering an investment in one of two machines. The sewing machine will increase productivity from sewing 150 baseballs per hour to sewing 260 per hour. The contribution margin per unit is $0.54 per baseball. Assume that any increased production of baseballs can be sold. The second machine is an automatic packing machine for the golf ball line. The packing machine will reduce packing labor cost. The labor cost saved is equivalent to $25 per hour. The sewing machine will cost $360,000, have an eight year life, and will operate for 1,700 hours per year. The packing machine will cost $120,000, have an eight year life, and will operate for 1,600 hours per year. All Star seeks a minimum rate of return of 15% on its investments.