Minitab Instructions/Lab Side-by-Side Boxplot
For comparing data sets
Data: Driving data for males and females

The process to create side-by-side boxplots requires that the data be arranged in a particular format.
Instead of having the seperate data sets in different columns, we need to have them in one column, stacked on top of each other. For example, assume we have the driving data for males and females entered into Minitab as follows:

 
C1
C2
 
Males
Females
1
100
110
2
102
95
3
80
85
4
120
82
5
110
80
6
90
90
7
120
90
8
etc
etc

We next need to manupulate the data to look like this...

 
C1
C2
 C3 C4
 
Males
Females
 Gender Driving Times
1
100
110
 m
100
2
102
95
 m
102
3
80
85
 m
80
4
120
82
 m
120
5
110
80
 m
110
6
90
90
 m
90
7
120
90
 m
120
8
etc
etc
 etc
etc
      f
110
      f
95
      f
85
      f
82
      f
80
      f
90
      f
90
      f
etc

Data Manipulation Directions:
Type in the variable headings into columns 3 and 4:
 Here C3: Gender and C4: Driving Times
Next choose Manip from the tool bar:
            Manip > stack > Stack Columns…>
            Select (double click) the two columns to be stacked
                        Here:  Male and Female
            Bullet:  Columns of current worksheet:  choose C4: Driving Times(numeric)
Store subscripts in:  choose C3: Gender (character)
OK

Notice that the driving times data are stacked; male time first, then female. Notice also, the gender column which associates each respective driving time.

 

 

Once the data has been manipulated in the appropriate format, we are ready to make side-by-side boxplots
To create side-by-side-boxplots:
Select Graph menu and highlight Boxplot...
In the Y column select data in C4 (this is the stacked numeric variable)
In the X column select data in C3 (this is the stacked character variable)
Optional: Transpose X and Y OK
Select [Annotation] > title: “enter a title name” OK
OK

Lab: Use the driving_data for males and females. Use Minitab to create side-by-side boxplots.