27. 2.103 The Pedernales Electric Cooperative estimates that the present worth now of income from an investment in renewable energy sources is $12,475,000. There will be no income in years 1 and 2, but in year 3 income will be $250,000, and thereafter it will increase according to an arithmetic gradient through year 15. What is the required gradient, if the interest rate is 15% per year? Solve using (a)

factors, and

(b) a spreadsheet with the GOAL SEEK tool.