Proportions of a Normal Distribution Calculator
Proportions of a normal distribution calculator is an essential tool for understanding and working with normal distributions. It helps in calculating the proportion of data that falls within a certain range of standard deviations from the mean.
- Enter the mean, standard deviation, and z-score values.
- Click ‘Calculate’.
- View the results and chart below.
The formula used is P(Z < z) = (1 + erf(z / sqrt(2))) / 2, where erf is the error function.
| Z-Score | Proportion |
|---|---|
| 0 | 0.5 |
| 1 | 0.8413 |
| 2 | 0.9772 |
- Always use the standard deviation to determine the spread of the data.
- Z-scores help compare data with different means and standard deviations.
What is a normal distribution?
A normal distribution, also known as a Gaussian distribution, is a continuous probability distribution that is symmetric about its mean and has a bell-shaped curve.