## Planet centurion

This is a level 3 statistics activity from the Figure It Out theme series. A PDF of the student activity is included.

## About this resource

*Figure It Out* is a series of 80 books published between 1999 and 2009 to support teaching and learning in New Zealand classrooms.

This resource provides the teachers' notes and answers for one activity from the* Figure It Out* series. A printable PDF of the student activity can be downloaded from the materials that come with this resource.

Specific learning outcomes:

- Construct a bar graph.
- Interpret data from a graph.

# Planet centurion

## Achievement objectives

S3-1: Conduct investigations using the statistical enquiry cycle: gathering, sorting, and displaying multivariate category and whole number data and simple time-series data to answer questions; identifying patterns and trends in context, within and between data sets; communicating findings using data displays.

## Required materials

*Figure It Out, Level 3, Theme: Time Travel,*"Planet centurion", page 17- square grid paper

See **Materials that come with this resource** to download:

*Planet centurion activity*(.pdf)

## Activity

This activity is about graphing data. The graphed data shows patterns in the data more clearly than data listed as numbers, and this makes the data easier to analyse.

When the students graph their data, make sure they plot the x-coordinate correctly. Although the x axis of the graph is marked with regular 100-year intervals, the data is not given at regular intervals. For example, the difference between the first and second plaques is 100 years, but the difference between the second and third plaques is 200 years.

The activity introduces the concept of an outlier, which is a piece of data that is outside the trend shown by the other data in a set. Discuss with the students how to recognise outliers in data displays. It is important for the students to investigate why outliers are sometimes present in data sets. Outliers are often the cause of a problem that researchers are trying to solve when they study data sets. Also, it is important to be aware of any outliers because they can affect the averages of data sets.

In question 3, the students have to extrapolate the data to estimate the average age in 2200. To do this, they continue the line of the graph, excluding the outlier, until they are directly above 2200 on the x axis. They can then see what number on the y axis they are aligned with.

As an extension, you could discuss the concept of life expectancy with the students and ask them why they think it fluctuates (that is, what causes increases or decreases in life expectancy). The students could then investigate how much life expectancy has changed in New Zealand over the last 200 years. They could look in the New Zealand Official Yearbook or on the website of Statistics New Zealand.

Note that life expectancies for men and women are different. You could discuss with the students why this could be.

You could link this activity to social studies with an investigation of life expectancies in countries around the world. The students could interpret events such as medical advances, economic prosperity, increased technology, and war as having a direct and graphic effect on life expectancy.

Discuss with the students if these events would lead to outliers in their data displays or alter the life expectancy trend in any way.

**1.**

**2.**

Around 1750, as this year lies outside the pattern formed by all the other years

**3.**

90 years

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