A correction which must be applied to the measured moments obtained from normally
distributed data which have been binned in order to obtain
correct estimators
for the population moments
. The corrected versions of the second, third, and fourth
moments are then
(1)
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(2)
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(3)
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where
is the class interval.
If
is the
th
cumulant of an ungrouped distribution and
the
th cumulant of the grouped distribution
with class interval
, the corrected cumulants (under rather restrictive conditions)
are
(4)
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where
is the
th
Bernoulli number, giving
(5)
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(6)
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(7)
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(8)
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(9)
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(10)
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For a proof, see Kendall et al. (1998).