What is the accumulated sum of each of the following streams of payments? a. exist510 a year for 9 years compounded annually at 10 percent. b. exist112 a year for 6 years compounded annually at 8 percent. c. exist37 a year for 11 years compounded annually at 12 percent. d. exist22 a year for 5 years compounded annually at 6 percent. a. What is the accumulated sum of exist510 a year for 9 years compounded annually at 10 percent? exist