STATISTICAL TECHNIQUES AND TOOLS
MEASURES OF VARIABILITY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Mean Deviation
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Range
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Standard Deviation
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Variance
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Detailed explanation-1: -It is the square of the standard deviation and is also known as the mean square . The most common used indicator of the degree of dispersion and is also the most dependable measure to estimate the variability in a total population. It gives equal weight to the deviation of every score in the distribution.
Detailed explanation-2: -Thus, the mean tells us what the average value is and the SD tells us what the average scatter of values is, around the mean.
Detailed explanation-3: -Standard deviation (SD) is the most commonly used measure of dispersion. It is a measure of spread of data about the mean. SD is the square root of sum of squared deviation from the mean divided by the number of observations. This formula is a definitional one and for calculations, an easier formula is used.