Weighted mean: what it means and how to read it
In the report: weightedMean. — The weighted mean with the weights in the column weightsCol, row by row; a zero, negative or missing weight leaves the row out, as SPSS WEIGHT. Empty when no row has a usable weight.
How to read it
An average where some rows count more — answers weighted to match the population, or group means weighted by group size.
In plain words
A student asked 100 classmates to rate the canteen from 1 to 10. Seventy answers came from girls and only 30 from boys, but the school is half girls and half boys. Girls gave 8 on average and boys gave 6. The plain average was 7.4, which leans towards the girls. She wanted a number for the whole school. She added a column saying how much each answer counts and asked for wmean of it. The answer was 7. Now she can report a number that fits the whole school better. Rows where that column is empty, zero or below zero are left out.
How it is computed
Σ w·x / Σ wWhere you see it
STATS_DESCRIPTIVE— Column-wise descriptive statistics with flexible metric selection and optional column filtering.
Related values
- Standard error — The standard error of the estimate: how much it would vary from sample to sample.
- Number of values — The number of values (rows) the result is computed on.
- Sum — The sum of the values; empty for a column without a single number (the sign . in a STATS_COMPUTE row where no item is answered), not 0.
- Mean — The arithmetic mean: the sum divided by n.
- Median — The middle of the sorted values; with an even n, the mean of the two middle ones.
Get it in your sheet
One formula in a cell gives the whole report, Weighted mean included. ALS Stats is a free add-on for Google Sheets™.
Install ALS Stats from Google Workspace Marketplace (opens in a new tab)