year 8 maths

550 Chapter 9 Data collection, representation and analysis
12 The ‘water footprint’ of different foods refers to the volume of fresh water that is used to produce
the food. The water footprint of some foods is shown in the table below.
Food bread cheese chicken cucumber lettuce milk potato rice
Footprint (L/kg) 1608 3178 4325 353 237 1800 287 2497
a What type(s) of graph could be used for the data above? Justify your choice(s).
b Choose a suitable type of graph and depict the above numbers graphically.
c How is a food’s water footprint related to how sustainable it is to produce?
d Estimate how many litres of water would be used for a chicken burger. Include your estimates
of each item’s weight.
e Another way to present the data is to say how many grams of each food is made from
1 kilolitre of water. Redraw the table above with a row for ‘water efficiency’, in g/kL .
ENRICHMENT
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13
Rearranging graphs
13 Consider the divided bar graph shown below.
A B C D
a Show how this graph will look if the segments are placed in the order C , D , A , B (from left
to right).
b In how many different ways could this divided bar graph be drawn (counting ABCD and
CDAB as two different ways)?
c If this bar graph is redrawn as a sector graph, how many ways could the segments be arranged?
Try to list them systematically. Do not consider two sector graphs to be different if one is just a
rotation of another.
Cambridge Maths NSW
Stage 4 Year 8 Second edition
ISBN 978-1-108-46627-1 © Palmer et al. 2018
Cambridge University Press
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