Box Plots are another way (other than dot plots) of organizing numerical data.
Inorder to create a box plot we need break the data into four equal groups and figure out the 5-Number Summary:
Minimum (the smallest data point)
Q1 (First Quartile)
Median or Q2 (the middle number or the Second Quartiel)
Q3 (Third Quartile)
Maximum (the largest data point)
Plot these five points on a number line and then connect them to make them look like a box plot. (See the picture below)
You can also find all of these things using your graphing calculator! Which makes if so much easier!
What would a skewed box plot look like?
One of the whiskers would be longer than the other and the median would not be centered in the box.
What would a symmetrical box plot look like?
Both whiskers would be about the same length and the median would be cenerted in the box.
For what type of data would it be best to use a box plot?
For skewed data, becuase it show the median and that is the best measure of center for that type of data.
What percentage of the data is located in each quartile?
25%! (because you seperated the data into 4 equal parts!)