representation. n. 1. the act or an instance of representing or the state of being represented. 2. anything that represents, such as a verbal or pictorial portrait. 3. anything that is represented, such as an image brought clearly to mind.
The standard deviation and range are both measures of the spread of a data set. Each number tells us in its own way how spaced out the data are, as they are both a measure of variation. The range relies on a very simple formula of subtracting the minimum data value from the maximum.
To calculate the Variance, take each difference, square it, and then average the result: So the Variance is 21,704. And the Standard Deviation is just the square root of Variance, so: And the good thing about the Standard Deviation is that it is useful. Now we can show which heights are within one Standard Deviation (147mm) of the Mean: