diff -r cdb7f31a7e10 Doc/library/statistics.rst
--- a/Doc/library/statistics.rst Sat Feb 08 19:58:04 2014 +1000
+++ b/Doc/library/statistics.rst Sat Feb 08 20:02:24 2014 +1000
@@ -271,13 +271,13 @@
.. function:: pvariance(data, mu=None)
Return the population variance of *data*, a non-empty iterable of real-valued
- numbers. Variance, or second moment about the mean, is a measure of the
- variability (spread or dispersion) of data. A large variance indicates that
- the data is spread out; a small variance indicates it is clustered closely
- around the mean.
+ numbers representing the entire population. Variance, or second moment about
+ the mean, is a measure of the variability (spread or dispersion) of data. A
+ large variance indicates that the data is spread out; a small variance
+ indicates it is clustered closely around the mean.
- If the optional second argument *mu* is given, it should be the mean of
- *data*. If it is missing or ``None`` (the default), the mean is
+ If the optional second argument *mu* is given, it should be the population
+ mean μ of *data*. If it is missing or ``None`` (the default), the mean is
automatically calculated.
Use this function to calculate the variance from the entire population. To
@@ -346,13 +346,13 @@
.. function:: variance(data, xbar=None)
Return the sample variance of *data*, an iterable of at least two real-valued
- numbers. Variance, or second moment about the mean, is a measure of the
- variability (spread or dispersion) of data. A large variance indicates that
- the data is spread out; a small variance indicates it is clustered closely
- around the mean.
+ numbers representing a sample from the larger population. Variance, or
+ second moment about the mean, is a measure of the variability (spread or
+ dispersion) of data. A large variance indicates that the data is spread out;
+ a small variance indicates it is clustered closely around the mean.
If the optional second argument *xbar* is given, it should be the mean of
- *data*. If it is missing or ``None`` (the default), the mean is
+ the sample *data*. If it is missing or ``None`` (the default), the mean is
automatically calculated.
Use this function when your data is a sample from a population. To calculate
@@ -414,5 +414,5 @@
Subclass of :exc:`ValueError` for statistics-related exceptions.
..
- # This modelines must appear within the last ten lines of the file.
+ # This modeline must appear within the last ten lines of the file.
kate: indent-width 3; remove-trailing-space on; replace-tabs on; encoding utf-8;