You wish to retire in $13$ years, at which time you want to have accumulated enough money to receive an annual annuity of $$28,000$ for $18$ years after retirement. During the period before retirement you can earn $9$ percent annually, while after retirement you can earn $11$ percent on your money.

What annual contributions to the retirement fund will allow you to receive the $$28,000$ annuity? Use Appendix $C$ and Appendix D for an approximate answer, but calculate your final answer using the formula and financial calculator methods.

Note: Do not round intermediate calculations. Round your final answer to $2$ decimal places.

Annual contribution