You can get slightly different answers depending on hows you set a couple of inputs, like
whether interest compounding is continuous or a simple annual rate / 12,
and whether payment is at beginning or at end of each period.
Example of slightly different results between:
..........................................Payment at start..............................Payment at end
...........................................of each period................................of each period
HP Financial calculator:.............$173.21........................................$173.97
Bank calculator:.......................$175.79.......................................$176.72
edit:
A real accurate financial calculator for de8212