1. After you graduate, you plan to work for another fifteen years and then retire and move to a low-cost area. You think you can save $4000 a year for the first 6 years following graduation, $5000 a year for the next 5 years, and $7500 a year for the last 4 years. If you can earn 6.0% a year placing your savings in a safe investment, how much will you have from these savings and the accumulated interest when you retire? Show your work in reaching this answer. MUST USE EXCEL TO SHOW WORK. PLEASE SHOW FORMULAS.