Cambridge International Mathematics

Continuous data (Chapter 17) 365

Review set 17B

1 The table alongside summarises the masses of 50 domestic cats

chosen at random.

a What is the length of each class interval?

b What is the modal class?

c Find the approximate mean.

d Draw a frequency histogram of the data.

e From a random selection of 428 cats, how many would you

expect to weigh at least 8 kg?

2 The table alongside summarises the best times of 100 swimmers who

swim 50 m.

a Estimate the mean time.

b What is the modal class?

Mass (mkg) Frequency

06 m< 2 5

26 m< 4 18

46 m< 6 12

66 m< 8 9

86 m< 10 5

106 m< 12 1

Frequency

256 t< 30 5

306 t< 35 17

356 t< 40 34

406 t< 45 29

456 t< 50 15

Time ( sec)t

6

0

10

20

30

40

50

60

70

80

90

0 102030405060

cumulative frequency

time ( minutes)t

The cumulative frequency curve

shows the time spent by people

in a supermarket on a given day.

Construct a cumulative

frequency table for the

data, using the intervals

,,and

so on.

Use the graph to estimate:

the median time

the IQR

the th percentile.

Copy and complete:

of the people

spent less than ......

minutes in the

supermarket

of the people

spent at least ......

minutes in the

supermarket.

05510

80

60%

80%

¡¡¡¡ ¡¡¡¡ 66 t< t<

a

b

i

ii

iii

c

i

ii

IGCSE01

cyan magenta yellow black

(^05255075950525507595)
100 100
(^05255075950525507595)
100 100
y:\HAESE\IGCSE01\IG01_17\365IGCSE01_17.CDR Thursday, 23 October 2008 12:36:32 PM PETER