> Note that the 5% values of 3K and 18K give an exact match,

Yeah, but in name only.  Such a voltage divider will have a 1/7 ratio with
up to +8.9% to -8.3% error.

> and there's no exact match using 1% resistors!

But there are available ratios that will still be much more accurate than
the 5% resistor "exact match" solution.  For example, using the "inexact"
combination of 10.7K and 1.78K ohm 1% resistors yeilds a 1/7 ratio with a
tolerance of +1.6% to -1.9%.

I recommend that anyone seriously using this Perl script modify it to show
the worst case error for each combination, taking into account the
resistor tolerances.


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