Statistics
Comparison against the plain average
The equal-weights case. Comparing it with the weighted result isolates how much the weights actually changed the answer.
The Formula
Plain Average = (v1 + v2 + v3) / n
The equal-weights case. Comparing it with the weighted result isolates how much the weights actually changed the answer.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| n | Number of observations | count | Identical in effect to assigning every weight the value one. |
What Each Symbol Means
ncount
Number of observations
Identical in effect to assigning every weight the value one.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate a weighted average page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate A Weighted Average, filed under Math. Every number the guide produces comes from substituting into this one line.