- ALL normal distributions with a mean μ, and standard deviation σ, follow this rule:
- 68% of all observations fall within one standard deviation of the mean -- within σ of
the mean μ
- 95% of all observations fall within two standard deviations of the mean -- within
2σ of the mean μ
- 99.7% of all the observations fall within three standard deviations of the mean --
within 3σ of the mean μ
Dr. Christina Hayes
Wilson 2-263
Department of Mathematical Sciences
Montana State University
Bozeman, MT 59717
phone: 406-994-6557
fax: 406-994-1789
christina.hayes@montana.edu
(Email will likely reach me faster than a phone call)
