Compute the future values of the following:

a$)$ An initial $$3,000$ compounded annually for $6$ years at $5\%$

b$)$ An initial $$3,000$ compounded annually for $7$ years at $10\%$

c$)$ An annuity of $$3,000$ for $6$ years at $5\%$

d$)$ An annuity of $$3,000$ for $7$ years at $10\%$