Your goal is to have $4M in your retirement account on the day you retire. At age 22 you begin making deposits of $10,000 at the end of every year into your retirement account.
a. If you expect your account to earn 8% per year, how many years will it take to reach your retirement goal?
b. If you expect your account to earn only 4% per year, how many years will it take to reach your retirement goal?