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

You are not logged in.

#1 2006-03-29 10:01:29

MathsIsFun
Administrator
Registered: 2005-01-21
Posts: 7,552

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

Offline

#2 2006-05-03 03:58:59

ganesh
Moderator
Registered: 2005-06-28
Posts: 15,142

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.

Offline

#3 2008-03-06 04:32:02

Daniel123
Member
Registered: 2007-05-23
Posts: 663

Re: Statistics Formulas

Product Moment Correlation Coefficient (PMCC)

The least squares regression line

y = a + bx

    and   

Where

Last edited by Daniel123 (2008-03-22 13:32:39)

Offline

#4 2008-03-06 04:41:49

Daniel123
Member
Registered: 2007-05-23
Posts: 663

Re: Statistics Formulas

Normal Distribution Function

Last edited by Daniel123 (2008-04-15 08:14:04)

Offline

#5 2008-12-07 00:50:57

ganesh
Moderator
Registered: 2005-06-28
Posts: 15,142

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.

Offline

Board footer

Powered by FluxBB