Doug and Tina plan to retire at age 70 and live to be 90. They project they will need pre-tax $100,000 (today's dollars) per year in retirement. They expect to both collect Social Security at age 70 and combined it will be $40,000 each year. They expect their investments to earn 6% annually, compounding monthly. They plan to withdraw equal amounts on the last day of each month throughout retirement. They are not concerned about leaving anything behind as an inheritance. How much will they need to have invested to sustain these withdrawals?