This video describes the concept of comparing two numerical variables. This builds on the video Random Variables, where variable type is described. There you can revisit how to identify whether a variable is numerical. A numerical variable is a variable where the possible responses are numbers which reflect the quantity, or amount, of something. Take for example height, in centimeters, or weight, in kilograms. This also builds on the Correlation Video.

## Before You Watch

## Now What?

This video introduced how to determine the line of best fit to describe the relationship between two numerical variables. You can look to further develop your understanding of this concept by looking to the Other Links listed below. Alternatively, ensure that you are also confident with the material covered in Association Between Two Continuous Variables: Correlation as this video is closely related to this one.

## But When Am I Going to Use This?

Statistics is essential in the study of systems of situations where there is an unpredictable random element. This includes a huge number of situations, such as any system that involves living things, which always have a degree of unpredictability. In fact, any studies that involve people involve statistics: for example, medical processes, education and economics. Other areas statistics can be applied to include quality control, stars, nature, or how wear and tear affects machinery.

## Other Links

A YouTube video made by the **Statistics Learning Centre in NZ** gives an overview of data types using animation that is easy to understand and fun. Note that numerical data types has been given alternative names. Interval and ratio data are used instead of discrete and continuous. It is a slightly different approach but the same principle.

If you really want to understand types of data, along with appropriate statistics and graphs, you can learn on our new **Snack-size** **course**. Takes about an hour, and lots of fun!