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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8
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4096
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0
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6.8
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Detailed explanation-1: -Variance is a measure of dispersion whose square root is called the standard deviation. Since the given variance is 64 then the standard deviation will be the √64 which is 8.
Detailed explanation-2: -Let’s calculate the variance of the follow data set: 2, 7, 3, 12, 9. The variance is 13.84. To get the standard deviation, you calculate the square root of the variance, which is 3.72. Standard deviation is useful when comparing the spread of two separate data sets that have approximately the same mean.
Detailed explanation-3: -The standard deviation formula may look confusing, but it will make sense after we break it down. Step 1: Find the mean. Step 2: For each data point, find the square of its distance to the mean. Step 3: Sum the values from Step 2. Step 4: Divide by the number of data points. Step 5: Take the square root.