DATABASE FUNDAMENTALS
DATA WAREHOUSING AND DATA MINING
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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: -We know that the standard deviation is the square root of variance of the observations. We also know that the square root of any quantity is always positive or zero. Hence, the standard deviation is always non-negative.
Detailed explanation-2: -Standard deviation is always non negative.
Detailed explanation-3: -Hence, the standard deviation never is negative.
Detailed explanation-4: -It’s TRUE: Standard deviation is a square root of variance which cannot be negative. The variance is calculated by summing up all squared deviations from the data points away from the mean.
Detailed explanation-5: -Introduction to Statistics The variance of a data set cannot be negative, but the standard deviation can be negative. It can be observed that both of these can’t be negative since standard deviation is the square root of the variance, which is the average squared deviation from the mean. Thus, the answer is False.