Dataplot Vol 2 Vol 1

# WEIGHTED SUM OF DEVIATIONS FROM THE MEAN

Name:
WEIGHTED SUM OF DEVIATIONS FROM THE MEAN (LET)
Type:
Let Subcommand
Purpose:
Compute the weighted sum of deviations from the mean of a variable.
Description:
The weighted sum of deviations from the mean is defined as

where X is the response variable, W is the weights variable, and is the sample mean. The response variable and weights variable must have the same number of observations.

For this command, the weights are not normalized. However, at least one of the weights must be positive and none of the weights can be negative. Otherwise, an error message is reported.

Syntax:
LET <par> = WEIGHTED SUM OF DEVIATIONS FROM THE MEAN <x> <w>
<SUBSET/EXCEPT/FOR qualification>
where <x> is the response variable;
<w> is the weights variable;
<par> is a parameter where the weighted sum of deviations from the mean is saved;
and where the <SUBSET/EXCEPT/FOR qualification> is optional.
Examples:
LET A = WEIGHTED SUM OF DEVIATIONS FROM THE MEAN Y1 WEIGHT
LET A = WEIGHTED SUM OF DEVIATIONS FROM THE MEAN Y1 WEIGHT SUBSET Y1 > 0
Note:
Dataplot statistics can be used in a number of commands. For details, enter

Default:
None
Synonyms:
None
Related Commands:
 WEIGHTED SUM OF SQUARED DEVIATIONS FROM MEAN = Compute the weighted sum of squared deviations from the mean of a variable. WEIGHTED SUM = Compute the weighted sum of a variable. WEIGHTED SUM OF SQUARES = Compute the weighted sum of squares of a variable. WEIGHTED SUM OF ABSOLUTE VALUES = Compute the weighted sum of absolute values of a variable. WEIGHTED AVERAGE OF ABSOLUTE VALUES = Compute the weighted average of absolute values of a variable. WEIGHTED MEAN = Compute the weighted mean of a variable. WEIGHTED STANDARD DEVIATION = Compute the weighted standard deviation of a variable. WEIGHTED VARIANCE = Compute the weighted variance of a variable.
Applications:
Data Analysis
Implementation Date:
2012/06
Program:
```
LET Y = DATA 2 3 5 7 11 13 17 19 23
LET W = DATA 1 1 0 0 4 1 2 1 0
.
LET A = WEIGHTED SUM OF DEVIATIONS FROM THE MEAN Y W
```
The returned value is 3.8889.

Date created: 06/29/2012
Last updated: 06/29/2012