Mean deviation, Applied Statistics

First Moment of Dispersion or Mean Deviation

Mean deviation or the average deviation is the measure if dispersion which   is based upon all the items in a variable .It is the arithmetic mean of the deviations of the values from a measure of central tendency   In the words of Clark and schkade average deviation is the average amount of scatter of items distribution from either mean or the median ignoring sings of the deviations.

Thus it is a measure obtained by calculating the absolute deviations of each observation from the media or the mean, taking all deviations as positive, and then averaging these decimations by taking their arithmetic mean. Mean deviation from arithmetic mean is also called first moment of dispersion.

The following process is adopted for its calculation:

(1)   Choice of Average : Theoretically mean deviation may be computed from any average mean or median or mode but in practice median and mean   are popular, of the two the use of median is better since sum of the deviations of observations is the least from median, as such unless specifically    nothing is given in the question median should be used.

(2)   Ignoring sings:  In its computation the algebraic sings of the deviations are ignored i.e. all the deviations are taken as positive. To indicate deviations are absolute and sings are ignored.

(3)   Mean of the Deviations:  The total of sum of the deviations is divided by the number of items, the quotient or the result is the mean deviation.

(4)   Formula: Mean deviation is expressed by the greek letter small delta as such.

(5)   Mean deviation from Mean

(6)   Mean deviation from Median

(7)   Mean deviation from Mode

Coefficient of Mean Deviation: The purpose of comparing variations or dispersal between two or more different sets of data a relative measure is computed using the following formula .

Coefficient of mean deviation from mean =x/x

Coefficient of mean deviation from median=m/m

Coefficient of mean deviation from mode= z/z

Posted Date: 9/26/2012 7:37:44 AM | Location : United States







Related Discussions:- Mean deviation, Assignment Help, Ask Question on Mean deviation, Get Answer, Expert's Help, Mean deviation Discussions

Write discussion on Mean deviation
Your posts are moderated
Related Questions
#There were three types of food, and the researcher recorded which foods were bought. Peanut Butter Banana Hamburger 15

Level of Significance: α The main purpose of hypothesis testing is not to question the computed value of the sample statistic, but to make judgment about the difference between

The decision maker ranks lotteries according to the utility function (i) State the independence assumption. Does this decision maker satisfy it? (ii) Is this decision ma

A file on DocDepot in the assignments folder on doc-depot called bmi.mtp contains data on the Body Mass Index (BMI) of a population of Ottawa residents. The first column identifies

differance b/w big M mathod and two phase mathod

Admixture in human populations The inter-breeding amongst the two or more populations which were previously isolated from each other for the geographical or the cultural reason

(a) Average rainfall during the month of January is found to be 58 mm. A Class A pan evaporation recorded an average of 8.12 mm/day near an irrigation reservoir. The average

A study was designed to investigate the effects of two variables - (1) a student's level of mathematical anxiety and (2) teaching method - on a student's achievement in a mathemati

Importance and Application of probability: Importance of probability theory  is in all those areas where event are not  certain to take place as same  as starting with games of

The Case Study included information about the price for a full meal before and after the law change (in dollars).  Of interest is whether the differences in price for a full meal b