Hello everyone, hope all is well today, my name is Gilles Lamothe
and we are going to go over question 1 of the categorical variables.
In part we are going to discuss the Minitab component of the question.
Here from a census in 2006, we have some respondents who are asked to identify their mother tongue,
in particular, we are interested in the Aboriginal mother tongue.
We are given in the question a frequency table. For example, for the Cree language,
we had 77,970 which had identified Cree as their mother tongue.
And in part B, we are asked to illustrate the distribution with two different types of diagrams
So if we go in the solutions, we see that we used the Bar Chart
also used the Pie Chart. We'll show you how to do this with Minitab.
In particular, both of these are suitable since our categorical variables here has categories
which are mutually exclusive and so each person can only give one mother tongue.
So maybe Cree or Ojibway, they can only fall in one category.
We'll start by going to Blackboard, and in the folder called categorical variable,
click on that, and then we see a few questions, scroll down a bit
and then we see a file called mothertongue.txt
and so if I save as, right click in Windows or this is using two fingers on a Mac.
You save as and I'll just put it on a desktop. The name of the file is called MotherTongue.
And then we open that up in Minitab.
Now, if I go to Minitab, I'll go to file, and then open, and then we'll go to
"All Minitab files" on Windows. Here we actually select, "All"
you want to actually identify text file as well.
Go to the location where I saved the file. I saved it on a desktop.
the name of the file was MotherTongue and then open.
We'll have two columns.
One is the first column which is a categorical variable
the names of our categories
and in the second column, it's a numerical column
where we have the frequency for each one of our categories.
Once we enter our frequency table, we could have done this by hand as well,
we go to Graph and then I find Bar Chart,
I select values from a Table and then Simple graph is fine.
A graph variable is a variable with the frequencies or the relative frequencies
so this is column C2 so select this column
The categorical variable is the name of our categories.
This is column 1. I select that.
Here, by default, Minitab is going to give you vertical bars.
If I press ok, you can see that I have vertical bars.
The difficulty here is that we have categories with very long names
and so actually it might be better to use horizontal bars.
And so I'll redo this
So Graph, Bar Chart, Values from a table, Simple.
Then what I'll do is, I'll go to chart options
and then here if I want to select "Show Y as a Percent"
because I want to use relative frequencies,
I'll prefer to express the frequencies as percentages, so relative frequencies.
Then I'll go to Scale and then I'll select
Transpose Value and Category Scales and this will get me horizontal bars
Then I press ok and then I have my Bar Chart.
If you want to insert this chart into a Word document you might want to save it
and so we'll go to file and then "Save graph as".
You might want to choose a format that is suitable to insert into Word;
jpeg is fine, png, bnp, so there are different types of format and then you can save.
You might also want to modify your graph. So you can click on any component.
Here for example, I prefer to change percent of frequency.
It's actually better if I just say Percent, that's nicer.
And then here I can just write "Bar chart of mother tongue as the title which is much better
Now to create a Pie Chart, it's just as easy. You go to Graph, Pie Chart.
Here again, we have "Values from a table" so just select Chart values from a table
You'll have your categorical variable. This is the name of the categories which are in column 1.
And then the frequencies or relative frequencies as the Summary variables, which are in Column 2
and then I press ok
Here is my pie chart. So it's a Pie chart of Aboriginal Mother tongue.
Here, the legend Minitab calls it "Category".
It's actually better if I click on it and change it
Maybe I should use "Mother Tongue" as a title for this legend.
And this is the Pie chart constructed by Minitab.
That's it for part B of the question.
