This plot is broken into four different groups: the lower whisker, the lower half of the box, the upper half of the box, and the upper whisker.
Further reading edit External links edit).
Do the same to find the median of the two numbers to the right.Outliers are values that are much bigger or smaller than the rest of the data.If your score was in the upper whisker, you could feel pretty proud that you scored better than 75 of your classmates. .For the data set 1, 2, 3, 4, 5, the median number, 3, has 2 numbers before it and 2 numbers after.3 Adjusted box plots are intended for skew distributions.5, draw a plot line.Extreme Values the smallest and largest values in a data set.(4 5) /.5.The lower extreme should be the lowest number in the data set, or the minimum number.Question What's the lower extreme?
Now we need to find the median of the lower half of the data set; in our example it would be the median of the two numbers to the left.
Since 111 is less than 166.57, 111 is officially an outlier.
Any data not included between the whiskers should be plotted as an outlier with a dot, small circle, or star, but occasionally this is not done.
These are represented by a dot at either end of the plot.4, find the first and third quartiles.Find the smallest, and then the largest, numbers in your data set and mark them on the plot line.The data is ordered, so you just need to find the median or center.5 For a medcouple value of MC, the lengths of the upper and lower whiskers are respectively defined to.5 e 3 M C,.5 e 4 M C if M C.5 e 4 M C,.5 e 3 M C if .Find the extreme values : these are the largest and smallest data values.Notches are useful in offering a rough guide to significance of difference of medians; if the notches of two boxes do not overlap, wta gstaad prize money this offers evidence of a statistically significant difference between the medians.A popular convention is to make the box width proportional to the square root of the size of the group.These plots are used to show quartiles.