(Compound annuity) What is the accumulated sum of each of the following streams of payments?

a. $480 a year for 10 years compounded annually at 10 percent.

b. $112 a year for 8 years compounded annually at 7 percent.

c. $35 a year for 12 years compounded annually at 13 percent.

d. $23 a year for 4 years compounded annually at 5 percent.