Variance()

Category: Aggregate

Syntax: Variance ( field {; field...} )


Parameters:

fieldAny related field, repeating field, or set of non-repeating fields that represent a collection of numbers.

Data type returned: Number

Description:

Returns the variance of the non-blank values represented in the parameter list. Variance is a statistical measure of how spread out a set of values is.

The StDev() of a set of numbers is the square root of the Variance() of the set.

The difference between the Variance() and VarianceP() functions is that the Variance divides the sum of the squares by n-1 instead of by n.

Examples:

The Variance of a set of numbers can be calculated by summing the squares of the distance of each value from the mean, then dividing by n-1, where n is the number of values.

For instance, given the set of numbers 8, 10, and 12, the mean of the set is 10. The distance of each value from the mean is -2, 0, and 2. The squares of these distances are 4, 0, and 4, and the sum of the squares is 8. The Variance is 8 divided by (31), which is 4.

 Variance (8; 10; 12)


Returns 4.

 Variance (7; 11; 15)


Returns 16.







FileMaker 8 Functions and Scripts Desk Reference
FileMaker 8 Functions and Scripts Desk Reference
ISBN: 0789735113
EAN: 2147483647
Year: 2004
Pages: 352
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