Your aunt sally is looking forward to retirement, but she is concerned about having enough money to enjoy her golden years. sally wants to be sure that before she retires, she has saved enough money to cover the rest of her expenses for the rest of her life.

sally estimates that after retirement, she will spend $20,000 per year. based on average life expectations, she will probably live 15 years past retirement, but , asa a margin of safety, sally wants to have enough for 20 years.

what sum of money will sally need at her retirement to cover her financial needs for the rest of her life? assume that sally can earn 6% interest on her money.