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10.04 Other graphs

Lesson

Are you ready?

Can you read information from a  column graph  or  picture graph  ? Look for keys or scales on a graph to help you understand what information is being presented.

Examples

Example 1

The column graph shows the number of each type of car fixed by the local mechanic.

This image shows a column graph of the number of each car brand fixed by the local mechanic. Ask your teacher for more information
a

Which car brand does the mechanic fix most often?

A
BMW
B
Mitsubishi
Worked Solution
Create a strategy

Using the graph, identify the car brand with tallest column height.

Apply the idea

The tallest column height with a frequency of 28 is BMW. So the correct answer is option A.

b

How many Holden or Toyota cars did the mechanic fix in total?

Worked Solution
Create a strategy

Add the column heights of Holden and Toyota.

Apply the idea

The column height of Holdens is 8 and the column height of Toyota is 12.

\displaystyle \text{Total}\displaystyle =\displaystyle 8+12Add column heights
\displaystyle =\displaystyle 20Perform the addition
Idea summary

Check the scale on a column graph. The ticks or marks may not always be worth 1.

Different graphs with same data

This video looks at how we can display the same data different ways using different graphs.

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Examples

Example 2

A group of children are going shopping and are deciding which shop to visit first. This table shows the shops the children like best.

A picture graph showing the shops children like best. Ask you teacher for more information.
a

How many children like the toy shop best?

Worked Solution
Create a strategy

Count the number of images next to Toy shop.

Apply the idea

There are 7 images next to toy shop. So there are 7 children that like the toy shop best.

b

Complete the column graph to show the same data as the table.

A blank column graph for types of shops and the number of children that like them. Ask your teacher for more information.
Worked Solution
Create a strategy

For each shop draw a column that has a height that is equal to the number of children that like that shop best.

Apply the idea

We already know that 7 children like the toy shop, so the column above Toy shop should go up to 7.

From the graph we can see that 3 children like the sweet shop, so the column above Sweet shop should go up to 3.

From the graph we can see that 6 children like the game shop, so the column above Game shop should go up to 6.

The column graph shows the number of children that like different shops. Ask you teacher for more information.
Idea summary

We can read the data from one type of graph and display it in another type of graph.

Interpret graphs

This video shows us how to answer questions from graphs.

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Examples

Example 3

The pie graph below shows the results of a class survey where students were asked to nominate their favourite food:

The pie graph shows the results of a survey on favorite food. Ask you teacher for more information.
a

Which was the most popular food?

A
Noodles
B
Pizza
C
Burgers
Worked Solution
Create a strategy

Choose the largest area in the graph.

Apply the idea

The most popular food was burgers, since it takes up the most area in the graph. So the correct answer is option C.

b

Which food was as popular as noodles?

A
Pizza
B
Burgers
C
Nuggets
Worked Solution
Create a strategy

Choose the food with the same area as noodles.

Apply the idea

Noodles and nuggets have the same size areas, so nuggets are as popular as noodles. So the correct answer is option C.

Idea summary

When we use graphs, we need to figure out what it is telling us. We can use colours or pictures, or the size of a piece of the pie graph. We may also have labels on the graphs, so we need to check each graph to see what information we can use.

Outcomes

MA2-18SP

selects appropriate methods to collect data, and constructs, compares, interprets and evaluates data displays, including tables, picture graphs and column graphs M

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