Stats – Spring Semester
Computer Lab – Five-Number Summaries and Boxplots
name: ___________________________
In this lab, you will learn how to:
• Make boxplots with Data Desk.
• Find the five-number summary with Data Desk.
• Calculate mean and standard deviation with Data Desk.
• Find the five-number summary with Excel.
• Calculate mean and standard deviation with Excel.
In this lab, we will look at data from Sub-Saharan Africa. One set of data is the percent of women in
national parliaments in 2005. The other set is the percent of high school students that were female in
1999.
1. Boxplots with Data Desk
(a) Open the Excel file that contains the data. It is
in two worksheets. (See image)
(b) Select all of the cells that contain the data
including the data labels for the Women in
Parliament worksheet.
(c) Copy the selection into Data Desk.
(d) Click once on the “% female” variable so that
it is labeled as the “Y” variable.
(e) From the “Plot” menu, select “Boxplot Side by Side.”
(f) Increase the size of the window so that the boxplot is an appropriate size.
(g) Click on the arrow in the top left corner of the boxplot window and select “BoxPlot Options.”
(h) Choose the “Do not display” option and notice how the display changes.
(i) Make your boxplot look how you want.
(j) Copy and paste the boxplot into your Excel document.
2. Summary statistics with Data Desk
(a) From the “Calc” menu, select “Calculation
Options” and then select “Select Summary
Statistics…”
(b) Be sure all the boxes that correspond to the 5number summary are checked. Also select
“Skewness.”
(c) From the “Calc” menu, select “Summaries” and
then select “Reports”.
(d) Click on the window that displays the summary
statistics.
(e) From the “Edit” menu, select “Copy Window”.
(f) Choose the “Text only” option.
Stats – Spring Semester
Computer Lab – Five-Number Summaries and Boxplots
name: ___________________________
(g) Paste into your Excel document to the right of
the original data.
Enter Excel formula for
mean here.
3. Summary Statistics with Excel
(a) In the Excel document, to the right of the
statistics you just imported from Data Desk, we
will calculate all of the same statistics with
Excel.
(b) In the cell immediately to the right of the
imported mean, enter the Excel formula to find the mean (see chart below). Be sure to include all
of the cells that contain data (cell A2 to A43) and don’t forget the equals sign.
(c) Find all the other statistics: median, standard deviation, population standard deviation, minimum,
maximum, range, interquartile range, and the quartiles (Excel cannot calculate skewness.)
(d) Check to make sure the statistics you calculated with Data Desk match those you just found. Are
the quartiles the same?
4. If time allows…
(a) Do all the above for the second set of data, “Female High School Students.”
(b) Make conclusions regarding the summary statistics and displays for the two sets of data.
(c) What do you think it means when Data Desk says cases are missing? See below.
Excel Formulas
Statistic
mean
median
mode
sample standard deviation
population standard deviation
minimum
maximum
lower quartile
upper quartile
Formula
=average(range)
=median(range)
=mode(range)
=stdeva(range)
=stdevp(range)
=min(range)
=max(range)
=quartile(range, 1)
=quartile(range, 3)
Other Functions
Formula
Count the number of a certain data =countif(range, “criterion”)
value
Sum of a group of numbers
=sum(range)