STATISTICAL TECHNIQUES AND TOOLS
MEASURES OF VARIABILITY
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
Variability
|
|
No Variability
|
|
Either A or B
|
|
None of the above
|
Detailed explanation-1: -In simple terms, if the scores in a distribution are all the same, then there is no variability. If there are small differences between scores, then the variability is small, and if there are large differences between scores, then the variability is large.
Detailed explanation-2: -Variability is most commonly measured with the following descriptive statistics: Range: the difference between the highest and lowest values. Interquartile range: the range of the middle half of a distribution. Standard deviation: average distance from the mean.
Detailed explanation-3: -Subtract the mean from each score to get the deviation from the mean. Square each of these deviations. Add up all of the squared deviations. Divide the sum of the squared deviations by n – 1 (for a sample) or N (for a population).