Apple Numbers '08 - Manual (Page 275)

Chapter 12 Dictionary of Functions 275
STDEVA
The STDEVA function calculates the standard deviation of a set of values, including text
and Boolean values, based on the sample (unbiased) variance.
STDEVA(value, [value, . . .])
 value: One or more numeric or Boolean values or references to cells containing
numeric, textual, or Boolean values.
Notes
Unlike the STDEV function, which ignores cells that don’t contain numbers, STDEVA
assigns a value of 0 to any text value, 0 to the Boolean value FALSE, and 1 to the
Boolean value TRUE and includes them in the computation.
Entering text directly results in an error. Referencing a cell containing text is evaluated
as 0. Boolean values can be entered directly or as cell references.
For a data set containing only numbers, STDEVA returns the same result as STDEV.
STDEVP
The STDEVP function calculates the standard deviation of a set of values based on their
population (true) variance. This is appropriate when the specified values are the entire
population.
STDEVP(number, [number, . . .])
 number: A series of numbers or cell references.
Notes
The standard deviation is the square root of the variance returned by the VARP
function.
Examples
STDEV(5, 5, 5, 5, 6) returns a standard deviation of 0.447 based on an average of 5.2.
STDEV(1, 2, 3, 4, 5) returns a standard deviation of 1.58 based on an average of 3.
STDEV(1, 1, 1, 1, 6) returns a standard deviation of 2.24 based on an average of 2.
STDEV(2, 2, 4, 6, 6) returns a standard deviation of 2 based on an average of 4. Compare with
STDEVP(2, 2, 4, 6, 6), which uses the population (true) variance to return a standard deviation of 1.79.
Examples
STDEVA(TRUE, TRUE, TRUE, TRUE, 6) returns 2.24. Each TRUE value is counted as a 1.
STDEVA("a", 3, 6, 3, "b") displays an error.