This week we looked at box plots. A box plot represents a
set of data by showing the minimum, maximum, quartiles and median. Box plots are very useful when comparing two
sets of data as you can quickly see which data set is more spread out and which has
the higher median.
When you have a list of numbers, you can work out the median
and quartiles and then draw the box plot. For a reminder of how to find the
median and quartiles, look at this website.
If you don’t have the original data (ie if it has been grouped
in a table) then in order to do a box plot you have to first draw a cumulative frequency
graph and then estimate the median and quartiles using the method described
here.
Here’s your homework sheet.