Ford temp gauge can have internal 100 ohms resistor or external 100 ohm, 92 is close enough

Resistors hooked up that way is called a Parallel resistor circuit, which is much different than when you hook resistors up in series, which just adds resistance, i.e. 100 ohms + 100 ohms = 200 ohms total resistance in series

In Parallel you need to divide resistance

Parallel resistance calculator here:

Parallel Resistor Calculator R1 + R2 = equivalent resistor R resistance circuit equiv total resistor finder made easy piggyback = parallel - sengpielaudio Sengpiel Berlin
Easier to use a calculator than to do math yourself, but formula is there

If you have 92ohm(gauge) and then sender is 30 ohm cold, you get 22 ohm which would be close to HOT, 10ohms

If sender was 75ohm and gauge was 92ohm then you get 43ohm at the needle for COLD, and 9ohms for HOT

So looking at that, 22ohm should be about 1/2 on gauge, not HOT, it is not linear, its a curve, but near 1/2 should be accurate