Of the following dotplots order then from least variation to most variation.
A
B
C
D
Compare
From the above dotplots can you order the data sets A, B, C, D in order from least variation to most variation (that is from least spread out to most spread out).
[color=#ff0000]D, A, B, C[/color]
Range
We can find the range of these data sets by taking the largest number and subtracting the smallest number. [br]What is the range of these data sets?
6
Notice how all four data sets have the same range despite some being more spread out than others.[br]Range is a basic way to describe variation in data, but we need more advanced measurements.[br]We will use technology to measure standard deviations and variance.[br][br]What are three ways we can measure variation?
Definitions
The [i][b]standard deviation[/b][/i] of a data set is a measure of variation based on how far each data value deviates, or is different, from the mean.[br]The standard deviation[br][list][*]is never negative.[br][/*][*]is[color=#ff0000][u] zero [/u][/color]if all the data values are[color=#ff0000][u] equal, [/u][/color]and will get larger as the data spreads out.[br][/*][*]has the [color=#ff0000][u]same units[/u][/color] as the original data.[br][/*][*]can be highly [color=#ff0000][u]influenced by outliers, [/u][/color]similar to the mean.[br][/*][/list][br]When we square the standard deviation, this is called [b]variance[/b].[br]Which of the follow is true?