Topics
14. Data
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AustraliaNSW
Stage 3

14.10 Data in the media

Lesson
Practice
Lesson

Are you ready?

Can you read information from a range of different graphs? What are all the different types you have seen so far? Look for keys or scales on a graph to help you understand what information is being presented.

Examples

Example 1

A marketing company conducted a survey to determine the market share of smartphone manufacturers. They surveyed 4000 people, and the results are given in the table below:

ManufacturerResponses
\text{Apple}2051
\text{Samsung}967
\text{Huawei}531
\text{Other}451

Which pie chart most accurately represents this data?

A
A pie chart showing the data for smartphone market shares. Ask your teacher for more information.
B
A pie chart showing the data for smartphone market shares. Ask your teacher for more information.
C
A pie chart showing the data for smartphone market shares. Ask your teacher for more information.
D
A pie chart showing the data for smartphone market shares. Ask your teacher for more information.
Worked Solution
Create a strategy

Use the data given in the table to find the corresponding sectors.

Apply the idea

Let's start by looking at the market share of Apple. Since 2051 is more than half of 4000, the sector corresponding to Apple should take up more than half the circle. So options A and B are not correct.

If we add the responses of Huawei and Others, we get 531+451=982, which is just a little bit bigger than Samsung. So the Samsung sector should be about equal to the Huawei and Other sectors combined.

So the correct answer is option D.

Idea summary

We can use different kinds of graphs to show data, and some graphs are more suitable than others. In each case, we need to read the heading to see what the graph is showing us, as well as how our graph is labelled.

Data in the media

The media use data and graphs a lot, because graphs convey information in ways that make it easy to understand quickly. This video shows us some simple strategies to interpret graphs that you may be unfamiliar with.

Loading video...

Examples

Example 2

Did you know most of your body is made of water?

This graph shows on average, the percent of water that different body parts are composed of, as well as the average total percent of water in the body.

The image shows a graph for the water percentage of body parts. Ask your teacher for more information.
a

What percentage of cells are made of water?

Worked Solution
Create a strategy

Look for the percentage written above Cells on the horizontal axis.

Apply the idea

We can see from the graph that cells are made of 90\% water.

b

What percentage more of your blood is water than is your muscles?

Worked Solution
Create a strategy

Subtract the water percentage of muscles from the water percentage of blood.

Apply the idea

We can see from the graph that 85\% of blood is water, and 75\% of muscles is water.

\displaystyle \text{Percentage more}\displaystyle =\displaystyle 85\%-75\%Subtract the percentages
\displaystyle =\displaystyle 10\%

There is 10\% more water in your blood than your muscles.

Idea summary

When we see data in the media, we should look beyond what we first see. Some questions to ask include:

  • Who is publishing the data?

  • Do they have a reason to make the data look a certain way?

  • Has the data been displayed consistently?

Outcomes

MA3-18SP

uses appropriate methods to collect data and constructs, interprets and evaluates data displays, including dot plots, line graphs and two-way tables

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