Matt Awesome via EV wrote:
It's not that simple. There are huge variations, so the "average" doesn't
necessarily apply to all that many people
That's exactly what standard deviation is for, to know the probability
(or occurrence) of a given situation. A broadly spread dataset is
different from a tightly grouped dataset, and that's what standard
deviation tells you. Your criticism is already included in the model.
The way I used it is in proper context, so it makes sense.
The statistics are slippery. The extremes don't make the case. But neither
can you take the national average, and assume that everyone is like that,
right in the middle.
You're correct.
But that's not what I did. What I did includes everything you're
thinking about and more.
My (many decades old) memory of statistics is that a standard deviation
assumes a Normal distribution. I suspect that the distribution of how
many light are left on in a building is a long way away from normal.
We have this same debate every time someone mentions that the "average"
person drives 35 miles per day; so an EV with a 50-mile range is fine.
But everyone jumps in to say they don't know *anyone* who drives 35
miles/day -- they all drive 100+miles/day, or virtually no miles most
days. (Me; I just happen to be that lone data point that really *does*
drive about 35 miles/day. That's why plain old lead-acid EVs have always
worked for me).
--
Problems that go away by themselves will be back with friends.
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com
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