Boxplots and five number summary

Boxplots and the five number summary are useful for a variety of reasons in the statistics course. They are especially useful for getting a quick picture of the distribution of the data, doing exploratory data analysis and comparing two datasets. It is a very useful technique to know how to use your TI-83 to get this information and draw boxplots

To get a five number summary do the following

	Enter the data in a list (I'm using L1)
	Hit STAT
	Use the arrow keys to highlight CALC
	Choose 1-Var Stats
	Enter the name of the list (necessary if not L1)
	Hit enter and use the arrow keys to show the 5 number summary

Here is some data to work with - the ages of academy award winning actresses

50	44	35	80	26	28	41	21	61	38	49	33
74	30	33	41	31	35	41	42	37	26	34	34
35	26	61	60	34	24	30	37	31	27	39	34

Here is a demonstration of getting the five number summary with this data

Data entered in L1	Hit STAT CALC	Choose 1-Var Stats

Enter L1 (2nd 1)	Enter	Arrow down to get data

To draw a boxplot do the following

	Enter the data in a list (I'm using L1)
	Hit 2nd Y= for STAT PLOT
	Turn on a plot and choose the boxplot (5th one in the list)
	Make sure the correct Xlist is given and the frequency
	Hit Zoom 9 for ZOOM STAT

Here is an example with our data

Enter data in the list	Hit 2nd Y= for STAT PLOT	Turn on Plot

Select Boxplot and the correct Xlist and frequency	Hit Zoom 9 for the picture

You can use the TRACE Key and the arrow key to actually identify the five number summary on the boxplot as is illustrated in the picture below

You can modify the boxplot to see outliers also. You use the same procedure as before but instead of entering the 5th item on the graph list you enter the 4th item - here is a demonstration

Enter data in the list	Hit 2nd Y= for STAT PLOT	Turn on Plot

Select Boxplot and the correct Xlist and frequency	Hit Zoom 9 for the picture

You can use the TRACE key once again to see the five number summary and the outliers also