Cambridge International Mathematics

14 Assumed Knowledge (Geometry and graphs)

gh

ij

Magazines and newspapers frequently contain graphs and tables which display information. It is important

that we interpret this information correctly. We often usepercentagesin our analysis.

Example 3 Self Tutor

A survey was carried out amongst retired people

to see if they were worried about global warming.

The results were collated and a bar chart drawn.

a How many retirees were not concerned about

global warming?

b How many retirees were surveyed?

c What percentage of retirees were:

i a little concerned

ii very worried about global warming?

a 40 retirees were not concerned about global warming.

b 40 + 20 + 35 + 50 + 55 = 200retirees were surveyed.

ciThe percentage ‘a little concerned’

= 20020 £100%

= 10%

ii The percentage ‘very worried’

= 20055 £100%

=27:5%

G INTERPRETING GRAPHS AND TABLES [11.1]

X

Y

Z

E D

F

A

C a B

b

E D

F

b a

C

B

A

X

Y

Z

A

B

C

R

Q

P

0 102030405060

Not concerned

A little concerned

Concerned

Worried

Very worried

Number of people

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cyan magenta yellow black

(^05255075950525507595)
100 100
(^05255075950525507595)
100 100
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