Medical Statistics Principles

The Normal Distribution

Many biological variables follow a symmetrical bell-shaped curve known as the normal or Gaussian distribution.

• Mean, Median, Mode: In a perfect normal distribution, these three values are identical and located at the center of the curve.
• The Empirical 68-95-99.7 Rule: Approximately 68% of the data falls within one standard deviation of the mean, 95% within two standard deviations, and 99.7% within three standard deviations.