probably didn't tell you in school is that median voltage is 117
Looked at our TV - looked at our stereo receiver - looked at our toaster - our microwave - or refrigerator - everything I can find to look at. Little tags on almost every electrical device tells how much current they draw and what volts they run on. Guess what? Every single thing I can find says 120!!
In the Navy we had some very sophisticated equipment that had some very precise requirements. We had very specialized equipment to maintain our power supply so everything ran precisely as it was supposed to. What did we set our voltage at? Precisely and exactly 120 on the money at all times. That is what the Navy school taught me.