When you are evaluating projects by the present worth method, how do you know which one(s) to select if the projects are (a) independent and (b) mutually exclusive? Swagelok Enterprises is a manufacturer of miniature fittings and valves. Over a 5- year period, the costs associated with one product line were as follows: first cost of $30,000 and annual costs of $18,000. Annual revenue was $27,000, and the used equipment was salvaged for $4000. What rate of return did the company make on this product