Please solve correctly this problem with hand calculations and show formulas used to get the numbers and as soon as possible

4) (28 points) Amy has decided to make annual contributions over a 15-year period into a retirement fund. She wants to make her rst 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? 0) (8 points) If Amy would like the fund to have a balance at the time of the 10'11 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