Question

Give an example of a qualitative variable and an example of a quantitative variable (discrete or continuous.) Explain the common graphical displays designed for use with
(a) qualitative data and
(b) quantitative data.
Note: Please answer all questions above by Wednesday and respond to at least three peers by Saturday night. Please, give page numbers of your textbook or some web links to support your answer.

Answer 1

Answer:

Example of qualitative variable: hair colour.

Example of discrete quantitative variable: age.

a) Qualitative data displays are pie charts, histograms

b) Quantitative data displays are scatter and line graphs.

Step-by-step explanation:

A qualitative variable expresses a non-numerical quality of an object or person. For example, hair colour (brown, blonde, red...) or eye colour (green, blue, brown...).

A quantitative variable is a numerical value. For example, temperature (100 K, 2000 K...) or age (12 years, 20 years...).

A discrete quantitative variable can be obtained by counting, like the number of cars in a road. This is plotted in scatter graphs. For continuous variable, it can be obtained by measuring, like the height of your family members. This is plotted in line graphs.

• Pie charts: is a circular graphic that shows the statistics or number of people or objects with certain characteristics. For example, how many people have brown hair, how many are blonde and how many are redheaded.
• Histograms: they show vertical bars associated with the qualitative variable in the x-axis and the number of objects or people with that characteristic in the y-axis.
• Scatter: it is a graph with x and y axis and using Cartesian coordinates. Since it is for quatities, numbers can be represented as points.
• Line graphs: it is basically the same as a scatter plot but in this case the points can be joined by a line because the quantities are connected or are continuous.

Answer 2

Answer:

a) Pie and Bar Chart b) Dot Plot,  Bar Graph, Box Plot among others.

Step-by-step explanation:

a) Qualitative data examples.

There are some good examples of  qualitative data, or variables like gender, level of study, marital status, etc.

These qualitative variables can be better displayed graphically with the use of several graphics. But the options are more restricted since there is not much information to be taken out of these when the graphic is solely dedicated to qualitative variables.

(Check below)

b) Quantitative data.

On the other hand, quantitative variables are the countable ones. The Quantitative Data can be either Discrete (for Integer numbers) or Continuous for any number ∈ R.

There is a wider set of options for displaying quantitative data, for quantitative variables, because we can extract more information from them. Since all we want is to display the position of that variable, then we can use Dot plots, Bar Graph, etc. Trace curves, etc.

(Check it below)

Examples:

• Means of 6 groups (Dot plots)
• Ages (Bar Graphs).
• Volume of Largest Dams in South America