no excel, thank you in advance!

4) (28 points) Amy has decided to make annual contributions over a 15 -year period into a retirement fund. She wants to make her first contribution of $6,000 one year from now (t=1). She then plans to increase her annual contribution by $600 each year for the remaining years. The fund is expected to earn 15% per year compounded annually. She plans to retire in 15 years (from now). a) (12 points) Determine the amount of money in the retirement fund at the time of Amy's retirement. b) (8 points) What equal amount can she withdraw annually for a period of 10 years starting one year after retirement, if she wants to deplete (i.e., balance =0 ) the fund when the last withdrawal is made? c) (8 points) If Amy would like the fund to have a balance at the time of the 10th withdrawal equal to 50% of the balance it had when she retired, what equal amount can she withdraw annually for a period of 10 years starting one year after retirement