Box Plots

Single Set of data
Multiple Sets of data in one column
Multiple Sets of data in separate columns

Single Set of Data

The data (AGEDEATH) used in this example can be found in the Minitab folder under STUDNT14. The first three lines of the data are below.

Day	Month	Gender	Birthplace	Age
3	1	Male	MA	87
5	1	Male	NJ	83
31	12	Male	NY	42
.	.	.	.	.

1.To make a boxplot of the data, go to the Graphs pull down menu and go down to boxplot. The following window will appear.

2.Select Simple under Y1. Click O.K. A new window will appear.

3.Click on the variable of which you would like to make a boxplot. The variable name should be listed under Graph variables:. Click O.K. The following box will appear.

Multiple Sets of Data in the Same Column

The data (AGEDEATH) used in this example can be found in the Minitab folder under STUDNT14. The first three lines of the data are below.

Day	Month	Gender	Birthplace	Age
3	1	Male	MA	87
5	1	Male	NJ	83
31	12	Male	NY	42
.	.	.	.	.

Suppose that you wanted to make a boxplot of the ages of death for men and women separately.

1.Go to Graph, Boxplot. You should get the following window.

2.Click on With Groups under One Y. Click o.k. The following screen should appear.

3.Put the quantitative variable (in this case age) in the Graph Variables: box. Put your grouping variable (in this case, gender) in the Categorical variables for grouping box. Click o.k. You should get the following boxplot.

4.In this graph, we have a boxplot for males and a boxplot for females. There is also a line appearing on the graph. This represents the age of the person for which we do not have their gender. We could remove this point and get the following graph.

Multiple Sets of Data for Data in Separate Columns
1. Your data should look like this. Each group of data should be listed in a separate column.

Type1 Type2 Type3
350        350         350
350        354         361
350        359         362
358        363         364
370        365         364
370        368         365
370        369         366
371        371         371
371        373         377
372        374         377
372        376         377
384        380         379
391        383         380
391        388         380
392        392         392

2. Go to Graph, Boxplots. The following window will appear.

3.Click on Simple under Multiple Y’s. Click o.k. Another screen will appear.

4.Enter the three sets of data in the box for Graph variables: and click o.k.

4.You will get the following boxplots in the above image.