BCom 1st Year Dispersion And Skewness Short Notes :-
SHORT ANSWER QUESTIONS
Q.1. What do you understand by dispersion? Give the measures.
Ans. Dispersion refers to the variability in the size of items. It is the spread or scatter of values om a measure of central tendency and is studied to have an idea of the homogeneity or heterogeneity of the frequency distribution.
‘Dispersion is the measure of variation of the items!
“The degree to which numerical data tend to spread about an average value is called the vallation or dispersion of data?
‘Dispersion is the degree of the scatter or variation of the variable about the central value.
Dispersion is used to indicate the facts that the items differ from one another in size within a given group. So there is a lack of uniformity in their sizes. Such measures give an average of the differences of various items from an average and hence they are also called as averages of second order.
The measures of dispersion are expressed in two terms :
1. Absolute Measure: In it, the dispersion is measured and expressed in terms of the original data. Such measures are not suitable for comparative studies.
2. Relative Measure: These measures are used for comparison purposes and are measured in terms of ratios or percentages. Such a measurement is called coefficient of dispersion.
Q.2. Define interquartile range and quartile deviation. Explain its merits and demerits. Ans. Interquartile range is a measure of partial range and is used to calculate the difference in the values of two quartiles, i.e. upper and lower quartiles, le. Q3 – Q1. Half of this difference is called the semi-interquartile range or quartile deviation. So, quartile deviation is the s which is half the distance along the series between the first and third quartiles.