Variability is a statistic representing the amount of dispersion in the data set. Measure of variability defines how far the data points tend to fall from the center.
If there is a low dispersion, then it indicates that the data points form a cluster around the center and if there is a high dispersion then it signifies they fall away from each other and from the center. The measure of variability is mainly used for finding 1. The range, 2. Interquartile range, 3. Variance, 4. Standard deviation.
- Range:- Range basically tells the spread of the given data from the lowest and the highest value in the given distribution. The range can be found simply by subtracting the lowest value from the highest value from the given data.
- Interquartile range:- The third quartile(Q3) minus the first quartile(Q1) is the interquartile range. This gives the range of the middle half of the data set.
- Variance:- The average squared difference of the values from the mean is given by variance. Variance is also the measure of dispersion that takes into the account spread of all data points in a data set.
- Standard deviation:- Standard deviation tells on an overall view of how far the data or the given values lie from the mean. There are six ways to find standard deviation:-
- List each data and find the mean.
- Substract each data from the mean to get deviation from the mean.
- Square each deviation.
- Square each deviation and ad them all.
- Divide the squared deviation’s sum by n-1 or N.
- Square root the number found.
