Z-Score Calculator
Calculate the Z-Score and P-Value.
How to Use
- Enter the raw score (x) for which you want to calculate the Z-score.
- Enter the population mean (μ) of your dataset.
- Enter the standard deviation (σ).
- Click 'Calculate' to find the Z-score and the corresponding p-value (area to the left).
About Z-Scores
A Z-score (or standard score) indicates how many standard deviations an element is from the mean.
Formula
Z = (x - μ) / σ Where: x = Raw score μ = Population mean σ = Population standard deviation
Interpretation
A Z-score of 0 means the score is exactly at the mean. A Z-score of +1 means the score is one standard deviation above the mean. A negative Z-score indicates the score is below the mean.
Key Features
- Calculates the exact Z-score.
- Approximates the p-value (cumulative probability) associated with the Z-score.
Applications
- Comparing scores from different normal distributions.
- Hypothesis testing in statistics.
- Identifying outliers in a dataset (typically |Z| > 3).