Why is 72 degrees considered room temperature?

Answer 1

It is not. 72 deg F is 22.22... deg C. Normal room temperature, for scientific purposes, is 20 deg C which is 68 deg F.

Answer 2

72 degrees Fahrenheit is often considered room temperature because it is a comfortable temperature for most people, where they neither feel too hot nor too cold. It is a common standard used for indoor climate control to create a pleasant environment for occupants.