John Jetison believes he would need $500,000 to retire today and keep his same lifestyle. If Jetison estimates he will retire in 20 years, how much should he put away each month to have the equivalent of $500,000 in 20 years if the interest he can earn is 5%? If the interest rate changes to 3%, what will Jetison need to save each month? Picture cash flows on a timeline and present it when providing your answer.