Oh boy, I caught myself being a real geek the other night.
My wife was watching Target. A clip about firewood was on (perhaps it was an old recording).
A pile of firewood had been separated for measurement - hard wood from soft wood. Soft wood was about two-thirds of the total pile. Dampness % were measured for the soft wood pile, then the hard wood pile, then a calculated average dampness for the total load.
A very damp pile, according to their expert.
I immediately insisted my wife press pause, I launched from my chair, loaded Excel and double checked their average calculation.
"AH HA!! they didn't do a weighted average! - how unfair is that?!"
I got rolled eyes and an unpause for my efforts...