Mr. smith has saved $1,200 each year for 20 years. a year after the saving period ended, mr. smith withdrew $7,500 each year for a period of five years. in the sixth and seventh years, he only withdrew $4,500 per year. in the eighth year, he decided to withdraw the remaining money in his account. if the interest rate were 8% per year throughout the whole period, what was the amount he withdrew at the end of the eighth year?