The problem was resolved in email.

The primary problem was knowing how to calculate overtime for Ohio. It is much simpler than Calif: just 1.5 time for hours worked over 40. So the formula in I2 should be:

=ROUND(H2 + MAX(0,H2-40)*0.5) * 9.25, 2)

There were also some formulas that require explicit rounding. But that issue was secondary and not related to the "difference".

Interestingly, the example Excel file demonstrates why "Precision As Displayed" should not be set in this case.

Work time was calculated for each day of the week and converted to decimal hours. The number of hours needed to be calculated exactly (not rounded), but they are formatted to display only 2 decimal places. Setting PAD would have rounded those values to 2 decimal places.