how to estimate anything
Post on 13-Feb-2017
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HOW TO ESTIMATE ANYTHINGLearning Night - 01/21/15
WHAT IM TALKING ABOUT TODAY What is a Fermi Estimation?
An example to get us going
Some tips and tricks
Try it yourself!
EVER WONDER HOW MANY OR HOW OFTEN SOMETHING HAPPENS?
HOW MANY PIANO TUNERS ARE IN SAN FRANCISCO?
PIANO TUNERS IN SF 1M people in SF
2 people per household
1/20 households have a piano
each piano tuned once a year
2 hours to tune a piano
tuners work full time for 40 hours a week
1M people / 2 people per household = 500K households
500K * 1 / 20 pianos/household = 25 000 pianos = 25 000 piano tunings per year
1 hour to tune a piano = 100 000 piano tuning hours
100 000 hours / 2 000 hours per piano tuner = ~50 piano tuners!
Satisfying personal curiosity
Trying to figure out whether or not Maroon 5 really crashed all those weddings
Top down vs. Bottoms up
Give a range!
Easy numbers = Good numbers
Key is make assumptions based on what you know
HOW MANY PEOPLE ARE NAMED JONATHAN IN THE WORLD?
LOL. WHAT A DOUCHE.
Jonathan is a Male name
50% of population is Male
Only Westernized civilizations will name kids Jonathan (2B people)
1/16 Males named some variation of Jonathan (Jon, John, Johnathan etc)
3B * 50% * 1/16 = 62.5M people named Jonathan
Fermi is for
"FERMI ESTIMATES WORK BECAUSE THE ESTIMATIONS OF THE INDIVIDUAL TERMS ARE OFTEN CLOSE TO
CORRECT, AND OVERESTIMATES AND UNDERESTIMATES HELP CANCEL EACH OTHER OUT. "