Build the monthly cash flow schedule $($in Excel$)$ for an agency mortgage pass thru security with the following information. Attach the Excel file to this assignment.

Principal $=$ $$750,000,000$

Pass thru rate $=6\mathrm{.}80\%$

WAC $=7\mathrm{.}80\%$

WAM $=335($all mortgage loans in the portfolio were originally due in $30$ years$)$

PSA $=200$