# Statistics 1 OCR formulae/equation

Equations and formulae for statistics 1. Includes permutations and combinations, correlation, variance, standard deviation and variance.

- Created by: Becky
- Created on: 10-04-13 18:54

First 128 words of the document:

Formulas/Equations for Statistics 1

Correlation

Is between -1 (strong negative) and 1 (strong positive)

R= SXY

(SXX)(SY Y )

SXX = xi2 - 1 2

n( xi)

SYY = yi2 - 1 2

n( yi)

SXY = xiyi - 1

n xi yi

Expectation = xipi

Variance = x2 - [(x)]2

2

Standard Deviation = 1 2

n xi - x

Permutations and Combinations

Number of ways of arranging objects = n!

p!

n!

Number of ways of arranging objects when more than one is alike = p!q !r!

Number of permutations for an ordered arrangement of r objects from n unlike objects = n!

(n-r)!

Number of combinations of r objects from n unlike objects = n!

r!(n-r)!

## Comments

No comments have yet been made