Additional Problem 1: Find the uniform annual amount that is equivalent to an arithmetic gradient series in which the first year's payment is $400, the second year's payment is $500, the third year's payment is $600, and so on, and there are a total of 15 payments. The annual interest rate is 9%. Additional Problem 2: Calculate the equivalent annual cost of fuel for mail trucks that records indicate costs $62,000 in year one, increasing by $800 per year through year six. Use an interest rate of 9% per year. I Additional Problem 3: Suppose that annual income from a rental property is expected to start at $1,500 per year and decrease at a uniform amount of $60 each year after the first year for the 20- year expected life of the property. The investment cost is $9,000, and i is 8% per year. Is this a good investment? Assume that the investment occurs at time zero (now) and that the annual income is first received at EOY one.