Mr. Pitkin bought a farm and promised to pay $6275 in 6 years with 7.5% simple interest and $8150 in 14 years with 10.75% simple interest. Later, Mr. Pitkin met with the lender requesting to pay $6325 at the end of 4 years and to make a final payment at the end of 11 years. Based on a simple interest rate of 13.5%, determine the amount required to settle the debt at the end of 11 years.