Measures of Dispersion Course Name Quantitative Techniques Course Code PGHRM1C003TM2C005T Course In Charge Anjali Pathania

Concept of Descriptive Statistics Descriptive Statistics is that branch of statistics that uses techniques to give meaning or description to raw data. Three major properties that describe a set of quantitative data are: The numerical value of an observation (also called central value) around which most numerical values of all other observations in the data set show a tendency to cluster around is called central tendency. The extent to which numerical values in data set are dispersed around the central value is called variation. The extent of departure of numerical values from symmetrical (normal) distribution around the central value in data set is called skewness Source: J.K. Sharma, Business Statistics

What is the difference in the three distributions???

Measures of Variability/ Dispersion Dispersion of values in any data set is indicated by the extent to which these values tend to spread over an interval rather than cluster closely around an average. Techniques used to measure extent of variation or deviation (also called degree of variation) of each value in data set from a measure of central tendency usually mean or median are called measures of dispersion (or variation ) Range Variance Inter -quartile Range Standard Deviation Coefficient of Variation Source: J.K. Sharma, Business Statistics

Understanding Standard Deviation

Standard Deviation: Ungrouped Data Source: J.K. Sharma, Business Statistics

Standard Deviation: Grouped Data Source: J.K. Sharma, Business Statistics

Understanding Variance

Variance Source: J.K. Sharma, Business Statistics

Variance and Standard Deviation: For Individual Series Example : The wholesale prices of a commodity for seven consecutive days in a month is as follows: Days : 1 2 3 4 5 6 7 Commodity price/quintal : 240 260 270 245 255 286 264 Calculate the variance and standard deviation. Source: J.K. Sharma, Business Statistics

Source: J.K. Sharma, Business Statistics

Variance and Standard Deviation: For Continuous Series Source: J.K. Sharma, Business Statistics

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