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

a$.$ $$500$ a year for $10$ years compounded annually at $11$ percent.

b$.$ $$108$ a year for $7$ years compounded annually at $9$ percent.

c$.$ $$38$ a year for $12$ years compounded annually at $11$ percent.

d$.$ $$26$ a year for $4$ years compounded annually at $4$ percent.