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

Statistics is the science which deals with the method of collecting, classifying, presenting, comparing and interpreting numerical data collected throw some light on any sphere of inquiry.

In modern times the field of utility of statistics has widened considerably, in ancient times statistics was confined only to the state but it embraces almost every sphere of human activity.

Terms |
Notation |
Formula |

Population mean | µ | ∑x/ N |

Population variance | σ^2 | ∑(x-µ)^2/N |

Population standard deviation | σ | √[∑(x-µ)^2/N] |

Sample mean | x? | ∑x/n |

Sample variance | s^2 | ∑(x - x?) ^2/ n-1 |

Sample standard deviation | s | √[∑(x - x?) ^2/ n-1] |

Mean absolute deviation | MAD | ∑|x - µ| / N |

Range | Range | Largest value – Smallest value |

Midrange | Midrange | (Largest value – Smallest value) / 2 |

Interquartile range | IQR | Q3- Q1 |

Coefficient of variation | CV | σ/µ (100) |

Discrete probability Mean Standard deviation |
µ σ |
∑ x P(x) √[∑x^2 P(x) - µ^2] |

Binomial probability Mean Standard deviation |
P(x) µ σ |
nCxp^x q^(n-x) np √npq |

Poisson probability Mean Variance Standard deviation |
P(x) µ σ^2 σ |
?^x e^*(-x) / x! ? ? √? |

Z score | z | (x- µ) / σ |

Correlation coefficient | r | SSxy/ √(SSxx * SSyy) |

Simple regression | y^ = a+ bx |