A pie chart is a popular alternative for displaying frequency, particularly when we want to emphasise the relative size of different categories of the data.

To draw a pie chart, we must decide how many degrees each of our categories represents. We do this by dividing the total in the category by the overall total, to find out what proportion of the circle that sector of the pie should take up. We then multiply that fraction (i.e. the proportion) by 360.

Example

Masha earned $100 from her after-school job. She spent it as follows:

T-Shirt: $20. Chocolates: $10, Cinema tickets: $10, iTunes downloads: $20, Savings: $30

Show this information on a pie chart.

Exercise

This is exercise 12B from page 180 in our textbook:

The answers are below:

(3.) (b) 12.5% (4.) (b) $60,000 (5.) (a) 1/6 (b) 372 people (6.) (b) $33,333,333

(c) Education: $22.7m, Public works: $16.7m, Services: $20.8m, Other: $55.6m

(7.) (a) 15.3% (b) x is 54º and y is 131º. (8.) 61