You are trying to be more accurate by .00077 for 3.23 but ignore .09272 for 3.73
The gear count called 3.23 is a lot closer to
3.42 count is to 3.42 and
3.73 Count is to 3.73
If trying to be accurate in calculations you typically don't round different figures to different decimal points.
You want three decimals 3.231 you got there from rounding up the 7 from 3.2307
The same applys with 3.73
Round down the 2 in 3.7272
Two decimal 3.73 ?
Then you need to round down your 3.231