DATABASE FUNDAMENTALS
WORKBOOK THEMES
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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: -The average of the squared differences from the Mean. Hence from the (i) and the (ii) we can say that the square of the standard deviation is equal to variance. So option B is the correct answer .
Detailed explanation-2: -Variance is derived by taking the mean of the data points, subtracting the mean from each data point individually, squaring each of these results, and then taking another mean of these squares. Standard deviation is the square root of the variance.
Detailed explanation-3: -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-4: -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. Variance: average of squared distances from the mean.