STATISTICAL TECHNIQUES AND TOOLS
MEASURES OF CENTER AND SPREAD
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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True
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False
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Either A or B
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None of the above
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Detailed explanation-1: -Standard deviation is the spread of a group of numbers from the mean. The variance measures the average degree to which each point differs from the mean. While standard deviation is the square root of the variance, variance is the average of all data points within a group.
Detailed explanation-2: -The variance and the standard deviation are measures of the spread of the data around the mean. They summarise how close each observed data value is to the mean value.
Detailed explanation-3: -The standard deviation is a summary measure of the differences of each observation from the mean. If the differences themselves were added up, the positive would exactly balance the negative and so their sum would be zero. Consequently the squares of the differences are added.