Xena is trying to decide how much to save for retirement. Assume she plans to save $25,000 per year with the first investment made one year from now. Xena thinks she can earn 7% per year on her investments and she plans to retire in 28 years, immediately after making her last $25,000 investment. a) How much will she have in her retirement account on the day she retires? b) If, instead of investing $25,000 per year, she wants to make one lump-sum investment today for her retirement that will result in the same retirement saving, how much would that lump sum need to be? c) If she expects to live for 45 years in retirement, how much can she withdraw every year in retirement (staring one year after retirement) so that she will just exhaust her savings with the 45th withdrawal (assume her savings will continue to earn 7% in retirement)? d) If, instead, she decides to withdraw $160,000 per year in retirement (again with the first withdrawal one year after retiring), how many years will it take until she exhaust her savings? e) Back to the retirement saving phase, if Xena plans to save $25,000 per year, but she wants to retire in 28 years with $3 million in her investment account, how high of an annual return does she need to earn on her investments