A loan of 20,000 is to be repaid in 13 equal annual payments each payable at year-end. Interest is at a 4% annual effective rate. Because the borrower is having financial difficulties, the lender agrees that the borrower may skip the 5th and 6th payments. Immediately after the 6th payment would have been paid, the loan is renegotiated to yield a 5% annual effective rate for the remaining 7 years. Calculate the new level annual payment for the remaining 7 years. (Answer: 2,783.65)

So my thought was that for the first 4 years he's paying (20000/13)*[(1.04)^4 - 1 / .04] = 6533.02

The last 7 years he's paying x[(1.05)^7 - 1 / .05]

So x[(1.05)^7 - 1 / .05] + 6533.02 = 20000

But I'm not getting the right answer ... am I setting it up correctly?