4. You have just turned 25 years old, and accepted a job offer. Now you must decide how much money to put into your retirement plan. The plan works as follows: Every dollar in the plan earns 8% per year. You cannot make withdrawals until you retire on your 60th birthday. After that, you can make withdrawals as you see fit. You estimate that to live comfortably in retirement, you will need $80,000 per year, starting at the end of the first year of retirement and ending on your 100th birthday. a. How much saving on your 60th birthday so that you can afford to spend $80,000 per year till you are 100? b. If you contribute the same amount to the plan at the end of every year that how much do you need to contribute each year to fund you retirement? c. If you can save 2% more per year until you retire, how much do you need to contribute the first year to fund your retirement? you work