(Compound annuity) What is the accumulated sum of each of the following streams of payments? a. $480 a year for 9 years compounded annually at 11 percent. b. $100 a year for 6 years compounded annually at 8 percent. c. $38 a year for 12 years compounded annually at 13 percent. 7W with d. $22 a year for 4 years compounded annually at 6 percent. s) About... a. What is the accumulated sum of $480 a year for 9 years compounded annually at 11 percent? $ (Round to the nearest cent.)