Bill, age 45, wants to retire at age 60. He currently earns $60,000 per year. His goal is to replace 80% of his preretirement income. He wants the retirement income to be adjusted for inflation. Bill has an investment portfolio valued at $150,000, which is currently earning 10% average annual returns. Bill expects inflation to average 3% and, based on his family health, predicts he will live to age 90. Bill is currently saving 7% of his gross income at each year-end and expects to continue this level of savings. Bill wants to ignore any Social Security benefits for purposes of retirement planning.