About normal probability paper
Probability paper stretches the Y axis by the inverse normal distribution, so a normally distributed sample falls on a straight line. Plot cumulative percentages against the measured value, read the mean off the 50% line and take the standard deviation from the slope. It is the classic hand method for checking whether data is normal.
Great for
- Checking data for normality
- Reliability and life-data plots
- Particle size distributions
- Quality control and process capability