Formula:

Celsius = (Fahrenheit - 32) * 5/9

Calculation:

1. Subtract 32 from the Fahrenheit temperature: 101.9 - 32 = 69.9

2. Multiply the result by 5/9: 69.9 * (5/9) = 38.83

Answer: 101.9 degrees Fahrenheit is equal to 38.83 degrees Celsius.