What is the present worth of each of the following given series of payments? (a) $9,000 at the end of each year for eight years at 6 percent compounded annually. (b) $1,500 at the end of each year for 10 years at 9 percent compounded annually. (c) $7,500 At the end of each year for six years at 7.25 percent compounded annually. (d) $5,000 at the end of each year for 30 years at 8.75 percent compounded annually.