Apple Numbers '08 - Manual (Page 285)

Chapter 12 Dictionary of Functions 285
Notes
The VAR function divides the sum of the squares of the deviations of the data points by
one less than the number of values to find the sample, or unbiased, variance (as
opposed to the population, or true, variance). This is appropriate if the data points are
only a sample of a larger data set. If the specified numbers make up the entire data set,
you should use the VARP function to find the population (true) variance.
VARA
The VARA function calculates the sample (unbiased) variance of a set of values,
including text and Boolean values. Text values and the Boolean value FALSE are
included as if they are the number 0, logical TRUE as a 1.
VARA(value, [value, . . .])
 value: One or more numeric or Boolean values or references to cells containing
numeric, textual, or Boolean values.
Notes
The VARA function divides the sum of the squares of the deviations of the data points
by one less than the number of values to find the sample, or unbiased, variance (as
opposed to the population, or true, variance). This is appropriate if the data points are
only a sample of a larger data set. If the specified numbers make up the entire data set,
you should use the VARP function to find the population (true) variance.
For a data set containing only numbers, VARA returns the same result as VAR.
Examples
VAR(5, 5, 5, 5, 6) returns a variance of 0.2 based on an average of 5.2.
VAR(1, 2, 3, 4, 5) returns a variance of 2.5 based on an average of 3.
VAR(1, 1, 1, 1, 6) returns a variance of 5 based on an average of 2.
VAR(2, 2, 4, 6, 6) returns a variance of 4 based on an average of 4.
Examples
VARA(TRUE, TRUE, TRUE, TRUE, 6) returns 5. Each TRUE counts as 1.
VARA("a", 3, 6, 3, "b") displays an error.