A home in Biloxi, Mississippi. Credit: TerryKelly/Getty Images Mississippi is the best state to live in post-retirement if you want your money to go the farthest, according to a new study.The Magnolia State has the lowest annual cost of living, and residents need $768,800 to retire comfortably.Iowa was second overall but had the best quality of life; seniors need $790,100 to live there comfortably in retirement. For many, deciding where to retire comes down to striking the right balance between cost of living and quality of life. A recent study by Neil Jesani Tax Advisors named Mississippi the best state to establish roots post-retirement if you want your money to go the farthest. What made the Magnolia State a clear winner? The study analyzed all 50 states on economic factors, such as cost of living, rent prices, annual healthcare costs, quality of life, and the four percent rule for withdrawals that prevents retirees from depleting their savings too early.…