Cambridge International Mathematics

Continuous data (Chapter 17) 363

5 The times taken for trampers to climb Ben Nevis were recorded and the results tabled.

Time (tmin) 1756 t< 190 1906 t< 205 2056 t< 220 2206 t< 235 2356 t< 250

Frequency 11 35 74 32 8

a Construct a cumulative frequency curve for the walking times.

b Estimate the median time for the walk.

c Estimate the IQR and explain what it means.

d Guides on the walk say that anyone who completes the walk in 3 hours 15 min or less is extremely

fit. Estimate the number of extremely fit trampers.

e Comment on the shape of the distribution of walking times.

6

0

5

10

15

20

25

30

35

40

0246810

cumulative frequency

weight ( kg)w

Cumulative frequency curve of watermelon weight data

Frequency

(Alan)

Weight

(wgrams)

Frequency

(John)

4 4006 w< 550 5

32 5506 w< 700 60

44 7006 w< 850 70

52 8506 w< 1000 60

44 10006 w< 1150 35

24 11506 w< 1300 20

200 totals 250

4 The weights of cabbages grown by two brothers on

separate properties were measured for comparison.

a Draw, on the same axes, cumulative frequency

curves for both cabbage samples.

b Estimate for each brother:

i the median weight

ii the IQR

c Compare the 60 th percentile weights.

d Compare the two distributions.

The given graph describes the

weight of watermelons.

Estimate the:

median weight

IQR

for the weight of the

watermelons.

Construct a cumulative

frequency table for the

data including a

frequency column.

Estimate the mean

weight of the

watermelons.

40

a

i

ii

b

c

The results are shown in the table:

IGCSE01

cyan magenta yellow black

(^05255075950525507595)
100 100
(^05255075950525507595)
100 100
Y:\HAESE\IGCSE01\IG01_17\363IGCSE01_17.CDR Tuesday, 18 November 2008 11:51:18 AM PETER