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| -rw-r--r-- | Doc/library/statistics.rst | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/Doc/library/statistics.rst b/Doc/library/statistics.rst index d0274e8..4a3a896 100644 --- a/Doc/library/statistics.rst +++ b/Doc/library/statistics.rst @@ -449,9 +449,9 @@ However, for reading convenience, most of the examples show sorted sequences. 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 is typically the mean of - the *data*. It can also be used to compute the second moment around a - point that is not the mean. If it is missing or ``None`` (the default), + If the optional second argument *mu* is given, it should be the *population* + mean of the *data*. It can also be used to compute the second moment around + a point that is not the mean. If it is missing or ``None`` (the default), the arithmetic mean is automatically calculated. Use this function to calculate the variance from the entire population. To @@ -521,8 +521,8 @@ However, for reading convenience, most of the examples show sorted sequences. 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 + If the optional second argument *xbar* is given, it should be the *sample* + mean of *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 @@ -538,8 +538,8 @@ However, for reading convenience, most of the examples show sorted sequences. >>> variance(data) 1.3720238095238095 - If you have already calculated the mean of your data, you can pass it as the - optional second argument *xbar* to avoid recalculation: + If you have already calculated the sample mean of your data, you can pass it + as the optional second argument *xbar* to avoid recalculation: .. doctest:: |