Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

## #1 2006-03-30 09:01:29

MathsIsFun

Offline

### Statistics Formulas

Statistics Formulas

Average (mean):

Binomial Probability Mass Function
The probability of getting exactly k successes out of n events where the probability of k on each event is p:

Mean:

Variance:

Standard deviation:

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

## #2 2006-05-04 01:58:59

ganesh
Moderator

Offline

### Re: Statistics Formulas

Poisson Distribution

Poisson distrubtion is the limiting form of the Binomial Distribution when n, the number of trials is very large, and p, the probability of success, is very small, np remains finite.
Let

A random variable X taking values 0,1,2 .. is said to have a Poisson distribution with parameter

if its proabability distribution is given by

where r=0,1,2....

The mean of the Poisson Distribution

The variance of the Poisson Distribution

The mean and the variance of the Poisson Distribution is equal to
.

Character is who you are when no one is looking.

## #3 2008-03-07 03:32:02

Daniel123
Power Member

Offline

### Re: Statistics Formulas

Product Moment Correlation Coefficient (PMCC)

The least squares regression line

y = a + bx

and

Where

Last edited by Daniel123 (2008-03-23 12:32:39)

## #4 2008-03-07 03:41:49

Daniel123
Power Member

Offline

### Re: Statistics Formulas

Normal Distribution Function

Last edited by Daniel123 (2008-04-16 06:14:04)

## #5 2008-12-07 23:50:57

ganesh
Moderator

Offline

### Re: Statistics Formulas

Standard Deviation

where

and
is the mean.

Standard Deviation

where d = x - A, where A is the Assumed mean.

Standard Deviation for Discrete series:
In discrete series when deviations are taken from Arithmetic Mean,

where

and
is the mean.

When deviations are taken from Assumed mean,

where d = x - A and A is the Assumed mean.

Variance

Variance is the square of Standard Deviation. The positive square root of the variance is defined as Standard Deviation.

Standard Deviation for the first 'n' Natural numbers is

Character is who you are when no one is looking.