year 8 maths

658
5 a lowest: 50 kg, highest 85 kg
b Weight Frequency
50−54 6
55−59 6
60−64 8
65−69 7
70−74 7
75−79 1
80−85 5
c i 35 kg
ii 60–64 kg
d Only teenagers were chosen, not including children or
adults.
6 a i 6.5 ii 6 iii 3.5 iv 9.5 v 6
b Mean and median have increased by 1, but IQR is the
same because all numbers have just increased by 1.
7 a Not enough people, and her friends might work harder
(or less hard) than other students.
b She could choose 10 people who worked less hard than
her.
8 a 40 b 400 c 10 hours
d 18
15
12
9
6
3
0
8 9 10 11 12
TV watched (hours)
No. of students
9 a four students
b two students
c 1 p.m.
d six students
10 a 105° b 25%
c
Chinese
chicken
Extended-response questions
1 a
No. of rainy days
b 66
12
10
8
6
4
2
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
Aug
Sep
2 a 40 b cheesecake c
Oct
7
40
Nov
Dec
d i yes ii no iii yes iv yes
e 80
Semester review 2
Angle relationships and properties of geometrical
figures 1
Multiple-choice questions
1 B 2 D 3 E 4 C 5 C
Short-answer questions
1 a 66 b 25 c 123
d 35 e 70 f 98
2 a x = 81, y = 99 b a = 75
c a = 62, b = 62 d a = 65, b = 65
e a = b = c = d = 100, e = 80
f x = 95, y = 85
3 a 48 b 45 c 60 d 75 e 121 f 75
4 a a = b = 90 b a = 73, b = 95 c a = 265, b = 30
5
70° 20°
70°
20°
hamburgers
pizza
20°
20°
70°
70°
Extended-response question
11 a 11 b 5 c 3.5 d 2
12 a 12
b 5
c 3.5
d 3
b = 65 (supplementary to a)
c = 65 (alternate to b)
d = e = 57.5 (isosceles triangle)
f = 122.5 (supplementary to d)
g = 122.5 (revolution angle = 360)
h = 180 (straight angle)
i = 295 (revolution)
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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