# Australian Bureau of Statistics

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 CensusAtSchool Australia

CaSQ 12B - Pie Graph of Eye Colour by calculating angles

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 How to: Get a Random Sample from CensusAtSchool Go to the CensusAtSchool Random Sampler to download a sample. Reference year: (select year) Sample size: 100 students Select questions: Eye Colour Location: Select location Year level: (select a range of year levels) To protect privacy there is a rule built into the sampler that the requested sample size cannot exceed 10% of the respondents for the parameters entered.

In the CensusAtSchool random sample find data for Eye Colour.

1. Record each colour and the frequency of students in a table like the one below. Write your fractions in simplest form.

 Eye Colour Tally Frequency Fraction Number of degrees for each fraction (see below) Brown Blue Green Grey Hazel Other

A pie graph shows each fraction of the whole as a sector. Each sector can be measured as an angle. The whole circle angle is 360 °.
For each eye colour you need to calculate its fraction of the whole before you can work out the angle size of its sector.

2. Calculate the number of degrees needed for each sector to represent each eye colour and show your working in the table above.

For example,in a class of 24, if there were 18 people with brown eyes:

 Eye Colour Tally Frequency Fraction Number of degrees for each sector (see below) Brown llll llll llll lll 18 360° = 270°

3. Construct a circle or ask your teacher for a coloured circle and fold in half then fourths to locate the middle. Use a protractor and pencil to mark and draw the sector representing each eye colour on your pie graph.