Your friend is celebrating her 50th birthday today and wants to start saving for her anticipated retirement at age 60. She wants to be able to withdraw $20,000 from her savings account on each birthday for 15 years following her retirement; the first withdrawal will be on her 61th birthday. Your friend intends to invest her money in the local savings and loan, which offers 6 percent return per year. She wants to make equal, annual payments on each birthday for her retirement fund. If she starts making these deposits on her 51th birthday and continues to make deposits until she is 60 (the last deposit will be on her 60th birthday), what amount must she deposit annually to be able to make the desired withdrawals on retirement?