Divide the combined amount from Step 3 by the price plus face value divided by 2, as in (C +(F-P)/n) / ((F+P)/2). That is, 3 divided by 95 ($100 plus $90 divided by 2) equals .0315789.
The final value from Step 4, multiplied by 100 to get a percentage, is the yield to maturity. Yield to maturity = (C +(F-P)/n) / ((F+P)/2). In the example, the yield to maturity equals 3.158 percent.