Note
Power law distributions have a well defined mean only if the exponent exceeds 1 and have a finite variance only when the exponent exceeds two. To apply the central limit theorem (and related statistics) to a power law distributed variable it is first necessary to ensure that the distribution has an exponent that exceeds 2.
Read more about this topic: Power Law
Famous quotes containing the word note:
“Poor old Jonathan Bing
Went home and addressed a short note to the King:
If you please will excuse me
I won’t come to tea;
For home’s the best place for
All people like me!”
—Beatrice Curtis Brown (1901–1974)
“And songs climb out of the flames of the near campfires,
Pale, pastel things exquisite in their frailness
With a note or two to indicate it isn’t lost,
On them at least. The songs decorate our notion of the world
And mark its limits, like a frieze of soap-bubbles.”
—John Ashbery (b. 1927)
“No, in your rural letter box
I leave this note without a stamp
To tell you it was just a tramp
Who used your pasture for a camp.”
—Robert Frost (1874–1963)