Please check my answer ($2901.84) and provide a detailed solution preferably by hand

A demand loan of $8000 is repaid by paymengs of $4000 after two years, $4000 after four years, and a final payment after six years. Interest is 8% compounded quarterly for the first two years, 9% compounded monthly for the next two years, and 9% compounded quarterly thereafter. What is the size of the final payment? Round the final answer to the nearest cent as needed. Round all intermediate values to six drcimal places as needed.

A demand loan of $8000.00 is repaid by payments of $4000.00 after two years, 54000.00 after four years, and a final payment after six years. Interest is 8% compounde thereafter. What is the size of the final payment? The final payment is $2901.84 (Round the final answer to the nearest cent as needed. Round all intermediate values to six decimal places as needed.)