Читать книгу Applied Biostatistics for the Health Sciences - Richard J. Rossi - Страница 58

For populations having mound-shaped distributions,

1 Roughly 68% of all of the population values fall within 1 standard deviation of the mean. That is, roughly 68% of the population values fall between the values μ−σ and μ+σ.

2 Roughly 95% of all the population values fall within 2 standard deviations of the mean. That is, roughly 95% of the population values fall between the values μ−2σ and μ+2σ.

3 Roughly 99% of all the population values fall within 3 standard deviations of the mean. That is, roughly 99% of the population values fall between the values μ−3σ and μ+3σ.