Use the benefit-cost ratio method to select the most economic scheme from the following three proposals, with a minimum attractive rate of return of 10 percent and an analysis period of 30 years. Using the figures of problem 1 conduct an internal-rate-of-return analysis for the selection of the most economic scheme. Compute the net present value of the following three projects, analyzed over a 40-year period, with a 12 percent minimum attractive rate of return. Use the benefit-cost ratio method to select the most economic scheme from the following three proposals, with a minimum attractive rate of return of 10 percent and an analysis period of 30 years. Using the figures of problem 1 conduct an internal-rate-of-return analysis for the selection of the most economic scheme. Compute the net present value of the following three projects, analyzed over a 40-year period, with a 12 percent minimum attractive rate of return