Insert the function PMT in cell B8. Use the values in cells A8, B3, and B7 as function arguments (the FV and Type are not required for this function). Enter B3 as a negative in the function since it is the present value of a future value. The interest rate is an annual rate and payments are made monthly. Make sure you enter the interest rate correctly taking into account the number of payments made each year. Check the Formula Result in the dialog box before selecting OK. This is an important step in building a spreadsheet. If it looks correct, continue with the next step. If not, check the function arguments for errors. A8 is 4.15% B3 is $25,000 B7 is 18 (in months)