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:
“The note of the white-throated sparrow, a very inspiriting but almost wiry sound, was first heard in the morning, and with this all the woods rang. This was the prevailing bird in the northern part of Maine. The forest generally was alive with them at this season, and they were proportionally numerous and musical about Bangor. They evidently breed in that State.”
—Henry David Thoreau (1817–1862)
“I note that the Africa loves to depict the grace of reptiles.”
—Zora Neale Hurston (1891–1960)
“Return our hymn,
like echo fling
a sweet song,
answering note for note.”
—Hilda Doolittle (1886–1961)