- 1-800-665-6601
- [email protected]

The empirical rule is used only for three numbers of standard deviations 1σ,2σ, and 3σ.

Distance from the mean |
Values within Distance |

µ±1σ | 68% |

µ±2σ | 95% |

µ±3σ | 99.7% |

If a set of data is normally distributed, or bell shaped

· approximately 68% of the data values are within one standard deviation of the mean

· 95% are within two standard deviations, and

· Almost 100% are within three standard deviation.

According to empirical rule,

Approximately 68% of the prices should fall within

µ±1σ= 1.42 ±1*0.08

= (1.42- 0.08, 1.42+0.08)

= (1.34, 1.5)

Similarly 95% of the prices should fall within

µ±2σ= 1.42 ±2*0.08

=1.42±0.16

= (1.42- 0.16, 1.42+0.16)

= (1.26, 1.58)

And 99.7% of the prices should fall within

µ±3σ= 1.42 ±3*0.08

=1.42±0.24

= (1.42- 0.24, 1.42+0.24)

= (1.18, 1.66)