3. You hope to retire in 25 years and want to deposit a single lump sum that will grow to $250,000 at that time. If you can now invest at 8 percent, how much must you invest to realize the $250,000 when needed? 4. You expect to have $250,000 available in a retirement plan when you retire. If the amount invested yields 8 percent and you hope to live an additional 20 years, how much can you withdraw each year so that the fund will just be liquidated after 20 years