year 8 maths

586 Chapter 9 Data collection, representation and analysis
Chapter summary
Graphs
Column graph
Sector graph
Divided bar graph
Line graph
Graphs
Data collection,
representation
and analysis
Measures of centre
numerical order
0, 1, 4, 4, 5, 6, 9, 30
Median
(middle) = 4 + 5
2
= 4.5
Mode (most frequent) = 4
59
Mean (average)
8 = 7.4
Number of
children
Score
0
1
2
3
4
Stem
0
1
2
Frequency distribution
tables
Stem-and-leaf plots
Leaf Key
1 1 3 1|5 means 15 km
2 5
0 3 8 7
Single scores
Number of families
Tally
ııı
ıııı
ıııı ıııı ı
ıııı
ıııı ı
Grouped scores
Age
range
0−4
5−9
10−14
Frequency
3
5
11
5
6
n = 30
Frequency
3
7
5
n = 15
=
Lines joining each
Frequency
Frequency
25
20
15
10
5
0
14
12
10
8
6
4
2
0
Histograms
Single scores
0 1 2 3
Number of siblings
Grouped scores
0−99
100−199
200−299
300−399
400−499
Number of words in story
lower half
1 5 7 9 10 11
Lower quartile
= Median
= 8
Measures of spread
Range = 28 − 1 = 27
IQR
= 19.5 − 8 = 11.5
Interquartile range
upper half
13 17 19 20 23 28
Upper quartile
= Median
= 19.5
Frequency polygons
column’s centre
0 1 2 3
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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