4. How much will you have to invest today in order to receive: a) $500,000 at the end of 10 years at 5.00 percent? b) $700,000 in 15 years at 7.00 percent? c) $100,000 each year for 30 years at 6.75 percent? d) $15,000 each month for 30 years (360 months) at 7.00 percent