Statistics
Probability from favourable outcomes
The definition for equally likely outcomes. The result always lies between zero and one, and multiplying by one hundred gives a percentage.
The Formula
P = n_fav / n_total
The definition for equally likely outcomes. The result always lies between zero and one, and multiplying by one hundred gives a percentage.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| n_fav | Favourable outcomes | outcomes | How many outcomes count as the event happening. |
| n_total | Total outcomes | outcomes | Every equally likely outcome in the sample space. |
| P | Probability | dimensionless | Between zero and one inclusive. |
What Each Symbol Means
n_favoutcomes
Favourable outcomes
How many outcomes count as the event happening.
n_totaloutcomes
Total outcomes
Every equally likely outcome in the sample space.
Pdimensionless
Probability
Between zero and one inclusive.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate probability 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 Probability, filed under Math. Every number the guide produces comes from substituting into this one line.