Pie Charts Flashcards

All 5 cards in this deck

How do you work out the angle for a category in a pie chart?

e.g. frequency $5$ out of a total of $40$

$\frac{\text{frequency}}{\text{total}}\times 360^\circ$; here $\frac{5}{40}\times 360^\circ = 45^\circ$.

How do you find the frequency represented by a sector of a pie chart?

e.g. a $90^\circ$ sector when the total is $60$ people

$\frac{\text{angle}}{360}\times \text{total}$; here $\frac{90}{360}\times 60 = 15$ people.

What are the steps to draw a pie chart from a frequency table?

e.g. Bus $5$, Walk $15$

1. Find the total frequency: $5 + 15 = 20$
2. Angles $= \frac{\text{frequency}}{\text{total}}\times 360^\circ$: $90^\circ$ and $270^\circ$
3. Draw a circle and measure the angles with a protractor, then label each sector

What do the angles of all the sectors in a pie chart add up to?

$360^\circ$.

True or false? If the 'walk' sector is larger in school A's pie chart than in school B's, then more pupils walk at school A.

False. Sectors show proportions, so you need both totals before comparing frequencies.