Go Graphic

Online Tutorial -

CG50: How to Draw Boxplots

CG50: How to Draw Boxplots

In this tutorial we're looking at how to draw side by side boxplots for two sets of data. You may find it easiest to reset the calculator before starting so that your screen matches the one in the video. The data I'm using here is the number of goals and the number of points, by Premiership teams in a season.

Let's type in both sets of data. Choose stats mode, type the x values first. Use execute between each value. When you've typed all the x values, move the cursor to the right and then type list two from the beginning. Notice these lists don't have to be for paired data.

To graph the data, choose graph. To specify the type of graph, go to set. Graph one defaults to a scatter diagram, so choose graph two and scroll down to change the graph type. Use the Arrow to view the second page of choices and choose MedBox. To show outliers on the box plot, scroll down to outliers and switch to on. And now execute to save.

If you go back to set and choose graph three, again, scroll down to the graph type as we did before and choose boxplot from the second set of options. We need to select list and enter list two and execute. And then press execute again to enter these settings. To see each boxplot in turn, press graph two to see the first boxplot. Choose 1 Var to see the statistics for this data set and scroll down to see the median and the quartiles. Press draw to return to the graph. And then exit to return to the menu. F3 shows you graph three in exactly the same way.

You may want to compare the two boxplots by putting them together on the same axes. Now this is done by changing which graphs are selected. Press select and scroll down to switch graph two to on (graph three is already on). Press draw to see both boxplots together. 1 Var now brings up the cursor onto one of the box plots. Scroll up or down to change which information you want to see.

You can find additional resources at education.casio.co.uk