Formulas and Functions

Function Description
“VARA” (page 300) The VARA function returns the sample (unbiased)
variance, a measure of dispersion, of a collection
of values, including text and Boolean values.
“VARP” (page 302) The VARP function returns the population (true)
variance, a measure of dispersion, of a collection
of values.
“VARPA” (page 303) The VARPA function returns the sample (unbiased)
variance, a measure of dispersion, of a collection
of values, including text and Boolean values.
“ZTEST” (page 305) The ZTEST function returns the one-tailed
probability value of the Z-test.
AVEDEV
The AVERAGE function returns the average (arithmetic mean) of a collection of numbers.
AVEDEV(num-date-dur, num-date-dur…)
 num-date-dur: A value. num-date-dur is a number value, a date/time value, or a
duration value.
 num-date-dur…:Optionally include one or more additional values. If more than
one num-date-dur value is specied, all must be of the same type.
Usage Notes
AVEDEV divides the sum of the numbers by the number of numbers to get the Â
average. The dierence (absolute value) between the average and each number is
summed and divided by the number of numbers.
If  num-date-dur contains date/time values, a duration value is returned.
Examples
=AVEDEV(2, 2, 2, 4, 4, 4) returns 1.
=AVEDEV(2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4) returns 0.6666667.
Related Topics
For related functions and additional information, see:
“Listing of Statistical Functions” on page 225
“Value Types” on page 36
“The Elements of Formulas” on page 15
“Using the Keyboard and Mouse to Create and Edit Formulas” on page 26
“Pasting from Examples in Help” on page 41
230 Chapter 10 Statistical Functions