Here's how to convert Fahrenheit to Celsius:

Formula:

°C = (°F - 32) × 5/9

Calculation:

1. Subtract 32 from the Fahrenheit temperature: 98.9 - 32 = 66.9

2. Multiply the result by 5/9: 66.9 × 5/9 = 37.17

Therefore, 98.9°F is equal to 37.17°C.