std.dev. (standard deviation)

Type

Statistical Operator

Purpose

The std.dev. operator calculates the standard deviation (the square root of the variance) in a set of data. The result usually appears as a statistic in the summary area at the end of a report.

Syntax

FIELDNAME|VARIABLE : std.dev.  [other statistical operators] ; | .

Returns

A numeric value.

Usage

Standard deviation is used as an indicator of variability in a set of data (68% of the data set is contained in the first standard deviation).

The std.dev. operator can also be used when creating a report using Query by Model. To generate the standard deviation in Query by Model, highlight the column whose standard deviation you want to calculate, then select std.dev. in the Summarize pick list.

Example

for MEMBERS with TOTAL DUE > 175 ;

list records

LAST NAME in order ;

TOTAL DUE : item sum std.dev. .

end

This script tells DataEase: (1) Process all the MEMBERS records that have a value greater than $175 in the TOTAL DUE field, (2) list the members by LAST NAME in alphabetical order, and (3) list each member's TOTAL DUE amount, the sum of these amounts, and the standard deviation in the report output.

The output from this script might look as follows: