Answer:
on an excel spreadsheet you have the following values:
since I don't know which values correspond to B5 and B6, I will guess that they are n and interest rate.
=PMT(4.5%,12,-16450.95) or =PMT($B$5,$B$6,-16450.95)
= $1,804.11
*The $ sets the cell as absolute reference. If you input 16450.95, the value will be negative.