Weighted mean
Non-negative relative weights. No weighted variance or uncertainty estimate is calculated.
WEIGHTED MEAN / TRANSPARENT METHOD
Weighted mean
One value and one non-negative weight per row. At least one weight must be positive. A zero weight contributes nothing; the row remains visible.
This tab’s workspace
Interactive examples
Predefined synthetic data only. The link shares the example, never your numbers or metadata. Loading an example replaces current fields.
01Enter your data
Example⇧ Import or paste a table
Choose options explicitly. Missing cells are flagged, not skipped.
X and Y must describe the same rows. Selecting one column twice is allowed but yields a self-comparison, not independent evidence.
Review the table before importing
Uses the columns and decimal format selected above. Row numbers refer to the parsed table including the header; completely blank rows may already have been ignored. No correction or exclusion is automatic.
At most 80 notices are displayed; every row is checked.
The report retains the original table, edits and excluded rows. It contains data: share deliberately. This is an editable local trail, not a certification.
Compare table columns
Select up to 8 numeric columns. Every selected cell must be valid; no individual missing values are removed. This is a descriptive comparison, not a test between groups.
Resume an analysis from a file
Open a .json file exported by StatNivo. Replaces current data and recalculates in this calculator; nothing is uploaded.
Raw data: up to 10,000 values per series.
Temporary storage is off unless you select the option.
02Read your result
Loading the local calculator…
Export, save and share
Undefined values: empty cells. No additional rounding in CSV files. CSV headings use stable English identifiers for software compatibility.
Temporary storage is off unless you select the option. Optional sessionStorage, off by default. Keeps text, table and settings across tools and languages in this tab. Browser session restoration can retain it. Use “Delete saved data” on a shared device. Nothing is uploaded.
Relative weights
For readability the plot displays at most 50 regularly selected rows; all rows are used in calculations and CSV. Coincident points may overlap.
Residuals against X
How we get the result
Inspect paired rows
50 rows per page. Original row positions are retained; CSV includes all observations.
UNDERSTAND, DON’T JUST CALCULATE
The method in practice
x̄w = Σ(wᵢ xᵢ) / Σwᵢ; wᵢ ≥ 0; Σwᵢ > 0
Credits and grades
With values 28 and 24 and weights 6 and 12, the weighted mean is (28×6 + 24×12)/18 = 25.33333. The ordinary mean is 26. Multiplying every weight by the same positive factor leaves the result unchanged.
Practical checks before using a result
Weights are relative non-negative importance or frequency values here. This calculator does not implement weighted variance or infer the meaning of the weights.
Importing from Excel without shifting pairs
Paste the entire table, select its real delimiter and header, then preview it. In decimal-comma data, use a semicolon or tab as the column delimiter. If Y is missing in row 3, fix that row rather than moving row 4 up.
Practical checks before using a result
Sample or population?
For 2, 4, 4, 4, 5, 5, 7, 9 the population SD is 2; sample SD is √(32/7) ≈ 2.13809. Choose the population formula when describing the full population of interest, not because the number is smaller.
Standard deviation or standard error?
Standard deviation describes the spread of observations. The usual standard error of the mean is sample SD / √n under independent sampling with finite variance. For sample SD 10 and n = 25, SEM = 2. Repeated dependent readings do not automatically count as 25 independent measurements.
Importing from Excel without shifting pairs
Paste the entire table, select its real delimiter and header, then preview it. In decimal-comma data, use a semicolon or tab as the column delimiter. If Y is missing in row 3, fix that row rather than moving row 4 up.