STATISTICAL TECHNIQUES AND TOOLS
MEASURES OF VARIABILITY
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
Divide the variance by 2.
|
|
|
Its a long process and I can’t explain it right now.
|
|
|
Find the mean and multiply it by the variance.
|
|
|
Take the square root of the variance.
|
Detailed explanation-1: -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-2: -The standard deviation is simply the square root of the variance. This is a useful and interpretable statistic because taking the square root of the variance (recalling that variance is the average squared difference) puts the standard deviation back into the original units of the measure we used.
Detailed explanation-3: -Standard deviation measures how data is dispersed relative to its mean and is calculated as the square root of its variance. The further the data points are, the higher the deviation.
Detailed explanation-4: -The standard deviation formula is, = √ ∑i=1n (xi – x̅)2 / N.