Tamarisk Company is considering the purchase of a new machine. The invoice price of the machine is $112,000, freight charges are estimated to be $2,800, and installation costs are expected to be $4,600. The salvage value of the new equipment is expected to be zero after a useful life of 4 years. Existing equipment could be retained and used for an additional 4 years if the company does not purchase the new machine. At that time, the equipment's salvage value would be zero. If the company purchases the new machine now, it would have to scrap the existing machine. Tamarisk's accountant, Thomas Anderson, has accumulated the following data regarding annual sales and expenses with and without the new machine: 1. Without the new machine, Tamarisk can sell 9,200 units of product annually at a per-unit selling price of $100. With the new machine, the number of units produced and sold would increase by 25%, and the selling price would remain the same. 2. The new machine is faster than the old machine, and it is more efficient in its use of materials. With the old machine, the gross profit rate is 28.50% of sales, whereas the rate will be 30% of sales with the new machine. 3. Annual selling expenses are $147,000 with the current equipment. Because the new equipment would produce a greater number of units to be sold, annual selling expenses are expected to increase by 10% if it is purchased. 4. Annual administrative expenses are expected to be $92,000 with the old machine, and $103,000 with the new machine. 5. The current book value of the existing machine is $37,000. Tamarisk uses straight-line depreciation. 6. Tamarisk management has a required rate of return of 15% on its investments and a payback period of no more than 3 years. (a) Calculate the annual rate of return for the new machine. (Round calculations in percentages to 2 decimal places, e.g. 15.25% and final answer to 1 decimal place, e.g. 15.2\%.)