Cambridge International Mathematics

ANSWERS 683

8a 1 b 43 c 10 d 1 e 21 :4%

9aA scatterplot as the data is discrete.

b Golf score data for Guy

10 a Stem Leaf

0

18

2997

3 47937591474

4 40233713844459122335

5 1380524971 Key: 5 j 1 means 51

b Stem Leaf

0

18

2799

3 13444577799

4 01122233333444455789

5 0112345789

cThe stem-and-leaf plot shows all the actual data values.

di 59 ii 18 e 22 :2% f 8 :9%

EXERCISE 5B

1aA and B are very similar, with minor variations.

Both are positively skewed.

bThe values of A are generally higher than the values of B.

A is negatively skewed and B is positively skewed.

cA is positively skewed, and B is almost symmetrical.

The values of B are generally higher than the values of A.

dA and B are very similar, and both are negatively skewed.

eA and B are very similar, and both are positively skewed.

fA and B are very similar, and both are symmetrical.

2 ‘Outside USA’ service makes Pedro happier than ‘Inside USA’

service. This is because there are generally fewer breakages with

the private company.

3aIn 2008 as the scores are more closely grouped.

bIn 2008 , 842 compared with 559 in 2007.

4a

bThe sales each month are quite similar for both years although

more houses were sold in total in 2007. (This is Northern

hemisphere data as more houses sell in warmer weather.)

5a Travel times to university

Alex (train) Stan (bus)

75189

7532 2 24589

6440 3 0112468

85142

55

06 Key: 4 j 2 means 42 min

bAs the bus data is less spread out, travelling by bus is more

reliable.

6a Golf driving distances

Amon Maddie

87 14

92 15 02

550 16 789

7442 17 45789

88310 18 002289

4211 19 4567 Key: 17 j 4 means 174 m

bYes, shots with Maddie’s driver are less spread out and

therefore more consistent. They are also generally longer

hits.

EXERCISE 5C

1aColour Sector angle

Green 88 o

Blue 78 o

Red 67 o

Purple 48 o

Other 78 o

b

2a

b

c Graduate %increase

Kaylene 252

Henry 84 : 8

We i 173

Matthew 49 : 8

dKaylene and Wei

3a i

ii

bEither; a personal preference.

80

85

90

95

100

012345 6 7 89

score

week

40

Real estate sales data 07-08

40 30 20 10 0 102030

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

0

2007 2008

Green

Blue

Red

Purple

Other

0

1000

2000

3000

Kaylene Harry Wei Matthew

after 5 years

after 10 years

income ($)

2000 1000 0 1000 2000 3000

Kaylene

Harry

We i

Matthew

0

after 5 years after 10 years

income ($)

Comparison of weekly incomes

4040 3030 2020 1010 00 1010 2020 3030 4040

JanJan

FebFebMarMar

MayMayAprApr

JunJun

AugAugJulJul

SepSep

OctOct

NovNovDecDec

0

5

10

15

20

25

30

35

40

Jan FebMar Apr MayJun Jul AugSepOct NovDec

IB MYP_3 ANS

cyan magenta yellow black

(^05255075950525507595)
100 100
(^05255075950525507595)
100 100
Y:\HAESE\IGCSE01\IG01_an\683IB_IGC1_an.CDR Thursday, 20 November 2008 4:08:30 PM PETER