(Compound annuity) What is the accumulated sum of each of the following streams of payments? a. $510 a year for 9 years compounded annually at 9 percent. b. $100 a year for 7 years compounded annually at 7 percent. c. $36 a year for 12 years compounded annually at 11 percent. d. $22 a year for 4 years compounded annually at 6 percent. a. What is the accumulated sum of $510 a year for 9 years compounded annually at 9 percent? $ (Round to the nearest cent.)