Answers 515 answers CHAPTER 1 Simple and compound interest Skills check 1 a $1 b $8.75 c $1.50 d $0.25 e $4 f $0.25 2 a 7.25 b 0.0725 c 0.2 d 0.002 e 0.125 f 0.001 3 a years b years c years d 2 years e 4 years f 2 years 4 a 450 b 525 c 21 000 d 1.157 625 e 1.083 f 1.877 Exercise 1A — Simple interest 1 2 3 16 $584.50 17 a The Big-4 Bank offers the best rates. b The Big-4 Bank charges 11 % p.a. for a loan while The Friendly Building Society charges 12% ( = 12 × 1% per month). 18 a $627.13 b $12 542.50 19 a i $1540.63 ii $6162.50 b Yes 20 a $2247 b $15 729 c 7 years Exercise 1B — Finding P , R and T 1 2 3 14 a Yes ($1112.50) b No c Yes ($1600 in 23 months) d Yes ($1281.60) Exercise 1C — Graphing simple interest functions 1a b 2a b c 1600 d $16 000 3a b c Answers a $136.00 b $56.70 c $145.25 d $110.40 e $255 f $336.89 g $178.57 h $43.88 i $11.76 j $229.68 k $544.05 a $103.50 b $2700 c $325 d $131.25 a $360 b $1020 c $27 700 d $17.70 e $13.67 4 C 5 A 6 B 7 B 8 B 9 A 10 D 11 B 12 A 13 $465.50 14 $25.50 15 $2418.75 a $3070 b $4400 c $5425 d $236.36 e $2500 a 10% b 6.25% c 80% d 2.125% or 2 % e 3.36% a 1 year b 18 months c 3 months d 7 years e 1 month 4 $1515.79 5 $2133.33 6 $352 7 24 months 8 3 years 9 C 10 B 11 B 12 D 13 A 1 4 -- 1 6 -- 2 3 -- 1 12 ----- 5 12 ----- 1 2 -- 1 3 -- 1 2 -- 1 8 -- No. of years 1 2 3 4 5 Interest $400 $800 $1200 $1600 $2000 No. of years 1 2 3 4 5 Interest $1600 $3200 $4300 $6400 $8000 0 1 2 3 4 5 500 Interest ($) Years 1000 1500 2000 0 0 1 2 3 4 5 6 7 8 910 2000 Interest ($) Years 4000 6000 8000 10 000 12 000 14 000 16 000 0 0 1 2 3 4 5 2000 Interest ($) Years 4000 6000 0 1 2 3 4 5 200 Interest ($) Years 400 600 800 1000 0 0 0 1 2 3 4 5 1000 Interest ($) Years 2000 3000 4000 0 1A ➔ 1C
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A n s w e r s
515
answ
ers
CHAPTER 1 Simple and compound interest
Skills check
1 a
$1
b
$8.75
c
$1.50
d
$0.25
e
$4
f
$0.25
2 a
7.25
b
0.0725
c
0.2
d
0.002
e
0.125
f
0.001
3 a
years
b
years
c
years
d
2 years
e
4 years
f
2 years
4 a
450
b
525
c
21 000
d
1.157 625
e
1.083
f
1.877
Exercise 1A — Simple interest
1
2
3
16
$584.50
17 a
The Big-4 Bank offers the best rates.
b
The Big-4 Bank charges 11 % p.a. for a loan while The Friendly Building Society charges 12% (
=
12
×
1% per month).
18 a
$627.13
b
$12 542.50
19 a i
$1540.63
ii
$6162.50
b
Yes
20 a
$2247
b
$15 729
c
7 years
Exercise 1B — Finding
P
,
R
and
T
1
2
3
14 a
Yes ($1112.50)
b
No
c
Yes ($1600 in 23 months)
d
Yes ($1281.60)
Exercise 1C — Graphing simple interest functions
1 a
b
2 a
b
c
1600
d
$16 000
3 a
b
c
Answers
a
$136.00
b
$56.70
c
$145.25
d
$110.40
e
$255
f
$336.89
g
$178.57
h
$43.88
i
$11.76
j
$229.68
k
$544.05
a
$103.50
b
$2700
c
$325
d
$131.25
a
$360
b
$1020
c
$27 700
d
$17.70
e
$13.67
4
C
5
A
6
B
7
B
8
B
9
A
10
D
11
B
12
A
13
$465.50
14
$25.50
15
$2418.75
a
$3070
b
$4400
c
$5425
d
$236.36
e
$2500
a
10%
b
6.25%
c
80%
d
2.125% or 2 %
e
3.36%
a
1 year
b
18 months
c
3 months
d
7 years
e
1 month
4
$1515.79
5
$2133.33
6
$352
7
24 months
8
3 years
9
C
10
B
11
B
12
D
13
A
14--- 1
6--- 2
3---
112------ 5
12------ 1
2---
13---
12---
18---
No. of years
1 2 3 4 5
Interest
$400 $800 $1200 $1600 $2000
No. of years
1 2 3 4 5
Interest
$1600 $3200 $4300 $6400 $8000
01 2 3 4 5
500
Inte
rest
($)
Years
1000
1500
2000
0
01 2 3 4 5 6 7 8 9 10
2000
Inte
rest
($)
Years
400060008000
10 00012 00014 00016 000
0
01 2 3 4 5
2000Inte
rest
($)
Years
4000
6000
0
1 2 3 4 5
200
Inte
rest
($)
Years
400
600
800
1000
00
01 2 3 4 5
1000
Inte
rest
($)
Years
2000
3000
4000
0
1A
➔
1C
Maths A Yr 12 - Answers Page 515 Wednesday, September 11, 2002 3:41 PM
Maths A Yr 12 - Answers Page 517 Wednesday, September 11, 2002 3:41 PM
518 A n s w e r san
swer
sExercise 2A — Inflation and appreciation1 $20 8002 a $618 b $48.15 c $1.91
d $579.60 e $932.403 a $878.05 b $901.764 $117.90 5 $619 6 $2.527 $1.20 8 $122.80 9 D
10 $500 11 $2350 12 $2460
Exercise 2B — Modelling depreciation1 a
b V = 100 000 − 10 000A2 V = 50 000 − 8000A
3 a
b $20 000 c 9 years4 a V = 6400 − 2000A
b c 4
5 a b $2000
6 a b $17 000 c 7
7 a i $160 000 ii $128 000 iii $102 400iv $81 920 b
8 B
b See part d.
d
e 6 years
Exercise 2C — Straight line depreciation1 $20 0002 a $1000 b $10 300 c $270 000
d $145 e $32 0003 a $7 125 000 b $3 750 0004 $10 6005 8 years6 a 6 years b 5 years
c 8 years d 7 years7 $2500/year8 a $4000/year b $12 500/year c $14 500/year9 $900/year
10 $25 00011 a $110 000 b $26 500 c $145012 $78 000
0
20 000
40 000
60 000
80 000
100 000
0 2 4 6 8 10
Val
ue (
$)
Age (years)
0
10 000
20 000
30 000
40 000
50 000
0 2 4 6 8 10
Val
ue (
$)
Age (years)
0
10 000
20 000
30 000
40 000
50 000
0 2 4 6 8 10
Val
ue (
$)
Age (years)
01000200030004000500060007000
10 2 3 4
Val
ue (
$)
Age (years)
0
4 000
8 000
12 000
16 000
20 000
0 2 4 6 8 10
Val
ue (
$)
Age (years)
0
120 000
240 000
360 000
480 000
620 000
0 2 4 6 8 10
Val
ue (
$)
Age (years)
9 aAge (years) Value ($)
New (0) 30 000
1 26 000
2 22 000
3 18 000
4 14 000
5 10 000
cAge (years) Value ($)
New (0) 30 000
1 24 000
2 19 200
3 15 360
4 12 228
5 9 830
0
40 000
80 000
120 000
160 000
200 000
0 2 4 6 8 10
Val
ue (
$)
Age (years)
0
6 000
12 000
18 000
24 000
30 000 Straight line valueDeclining balance
value
0 2 4 6 8 10
Val
ue (
$)
Age (years)
Maths A Yr 12 - Answers Page 518 Wednesday, September 11, 2002 3:41 PM
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Exercise 2D — Declining balance or diminishing value method of depreciation1 $20 4802 a $2220 b i $750 ii $3903 7 years4 $383 0005 a $5900 b $68 100 c $1200
d $62 100 e $39006 $61747 $676 0008 a $14 600 b $20 4009 A
Exercise 3C — The cost of a loan1 11.6%2 a 11.6% b 8.32% c 15.2%
d 10.6% e 12.2%3 a 8.32% b 8.66% c 9.01%
d 9.39% e 11.6% f 18.3%4 a $213 996 b $128 996 c 6.0704%5 9.01%6 Loan 17 a $231 546 b $200 745.60
c $145 593.608 Loan 2 – they will save $60419 C
10 a $341 376 b $337 57811 D12 a $562 279.20 b 6.25% c 5.8%
Exercise 3D — Loan repayments1 $674.252 a $90.46 b $341.25 c $819.84
d $1101.00 e $1515.543 a $400 b $3600 c $123.054 They will not need to increase their repayments.5 a $1510.20 b $1620.146 Yes. The repayment is $744 and the most he can
afford is $750.7 a $7000 b $1750 c $178 0008 a $733.40 b $174.80
Exercise 3E — Bonds, debentures and term deposits1 $3200 2 $315 3 $472.50 4 $15005 $1800 6 $612.50 7 B 8 A9 C 10 D 11 C 12 B
a $22.15 b $84.99 c $297a i $1406.25 ii $1350 iii $1321.88b No difference
a $2066.10 b $9.47a 8 cents b 12 cents
1998 Transaction Debit Credit Balance1 May Balance B/F 2132.203 May Cheq 4217 460.27 1671.937 May Deposit 230.16 1902.0917 May Cheq 4218 891.20 1010.8926 May Wages 1740.60 2751.4931 May Interest 5.69 2757.182 June Deposit 415.10 3172.288 June Cheq 4220 2217.00 955.2819 June Cheq 4219 428.50 526.7821 June Cheq 4222 16.80 509.9823 June Wages 1740.60 2250.5830 June Interest 2.87 2253.451 July Deposit 22.80 2276.254 July Cheq 4221 36.72 2239.5318 July Cheq 4223 280.96 1958.5726 July Wages 1740.60 3699.1731 July Interest 11.02 3710.19
a i $6.25 ii $13.35 iii $7.10b i $4.79 ii $4.76 iii –$0.03c i $10.94 ii $16.86 iii $5.92
3A➔
3F
Maths A Yr 12 - Answers Page 523 Wednesday, September 11, 2002 3:41 PM
524 A n s w e r san
swer
sExercise 3G — Investing in real estate1 a $2448.75 b $3656.25 c $12 0002 a $244.88 b $365.63 c $12003 a $77 256.37 b $124 228.12 c $448 8004 $80 7505 a $1873 b $3175.50 c $12 832.506 a $189 123 b $272 415.50 c $554 952.507 a $169 692.50 b $278 375 c $8682.508 $87459 $127 500
10 $146 45011 $289 500
Exercise 3H — Investing in the stock market1 $19 131.25 2 $2511.253 $5071 4 $15405 25 c/share 6 $1.50/share7 6 c/share 8 29.27 c/share9 a $1.224 million b $2.176 million
c 43.52 c/share10 a $5.22 million b $9.28 million
c $1.66/share11 $3.276 million12 4.57%
13
14 2.91% 15 D 16 $36417 a 6.6% b $1.06/share18 a $1.14 b $5.928 million19 8.5%20 a 0.59% b $10.64
c 6.44 c/share d 0.61%21 a $77.50 b 1.2% c 82.622 a $60 b 1.2% c 83.323 a 5000 b 0.75% c 133.324 23.3
Exercise 3I — Graphing share performance1 a
b $7.002 a
b $1.75
3 a
b $1.20
4 a
b $16.00
5 a
b $14.50
History of mathematics — The Wall Street Crash1 Soaring share prices were suddenly reversed.
2 Share prices declined rapidly.
3 People stopped investing, banks and businesses collapsed, unemployment rose and Hitler came to power.
History of mathematics — The Dow Jones Industrial Average1 Wall Street Journal journalists Charles Dow and
Eddie Jones.
2 30.
3 Sum of 30 stock prices divided by 0.2252.
4 Technology, telecommunications.
Chapter review1 a $1120 b $7187.50 c $1281.60
d $39.60 e $12 285.00
2 $6760
3 $191.02
4 6.15%
5 a $1250 b $124 873.64
Dividend Share price Dividend yield
$0.56 $8.40 6.7%
$0.78 $7.40 10.5%
$1.20 $23.40 5.1%
$1.09 $15.76 6.9%
$0.04 $0.76 5.3%
6.506.706.907.107.30
6.306.105.905.70
1–M
ay1–
Jun 1–Jul
1–Aug
1–Se
pt1–
Oct
Shar
e pr
ice
($)
Month
4.504.003.503.002.50Sh
are
pric
e ($
)
1–Ju
n1–
Jul
1–Aug
1–Sep
t
1–Oct
1–Nov
1–Dec
1–Ja
n
1–Feb
1–M
ar
1–Apr
1–M
ay
1.101.121.14
1.081.061.041.021.00
2.022.04
2.001.181.16
1–Jan
1–Fe
b1–
Mar1–
Apr
1–M
ay1–
Jun1–Jul
1–Aug
1–Se
pt1–
Oct
1–Nov
1–Dec
Shar
e pr
ice
($)
Month1–
Jan1–
Feb1–
Mar1–
Apr
1–M
ay1–
Jun1–Jul
1–Aug
1–Se
pt1–
Oct
1–Jan
1–Feb
1–M
ar
1–Apr
1–M
ay1–
Jun1–Jul
1–Aug
1–Sep
1–Oct
1–Nov
1–Dec
Shar
e pr
ice
($)
Month
14.00
16.00
10.00
12.00
1–Jan
1–Feb
1–M
ar
1–Apr
1–M
ay1–
Jun
1–Jan
1–Feb
1–M
ar
1–Apr
1–M
ay1–
Jun1–
Jul
1–Aug
1–Sep
t
1–Oct
1–Nov
1–Dec
Shar
e pr
ice
($)
Month
12.50
12.00
13.00
13.50
14.00
14.50
Maths A Yr 12 - Answers Page 524 Wednesday, September 11, 2002 3:41 PM
A n s w e r s 525
answ
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c $5137.217 a $596 844 b $18 8848 a 7.25% b 13.70%
c 25.65% d 14.11%9 a $18 223.20 b $4723.20 c 7%
10 Loan 211 $21.1512 a $316.75 b $599.40
c $2369.11 d $510013 a $2453.49 b $2618.0614 B 15 A 16 D17 $2700 18 $694.17 19 $252020 $5000 21 D22 a $1.08 b $1.1523 a $3.33 b $3.6424 $3075 25 $401.63 26 $236 425.4527 $270 662.50 28 $15 832.50 29 $46 687.5030 $1.93/share 31 $14.74/share 32 5.22%
33 1.6% 34 81.8 c/share35 a $260 b 2.5% c 40.436 a
b $18.00
CHAPTER 4 Populations, samples, statistics and probabilitySkills check1 a 0.375 b 0.083 c 0.813 d 0.5902 a 75% b 12.5% c 42.5% d 4%3 Answers will vary.4 a 4 b 4 c 3 d 7 e 15 a a = 8 b b = 9 c c = 22.5
d d = 17.5 e e = 10.56 Scale on axes, omitting certain values, giving a 3D
visual impression, using a non-linear scale on the axes.
7 a 73 b 7.3 c 7 d 6e 6 f 8 g 6 h 2
Investigation — Australia’s population and housing census1 This is a statistical collection of data to determine the
number of people in Australia on Census Night, the characteristics of these people and the dwellings in which they live.
2 All people in Australia on Census Night take part.3 It is compulsory.4 Questions asked include: age, marital status,
birthplace, income, type of dwelling, type of job… The questions have changed over the years to take into account changing social conditions of the population; such as language spoken at home, computer usage…
5 A census can provide information necessary for future planning.
6 The ABS has access to the information and details of individuals are protected by the Privacy Act.
7 All dwellings are issued with census booklets, which are delivered and collected by ABS workers. The booklets are completed by all individuals on the same night.
Exercise 4A — Populations and samples1 Census, sample2 Census — every member of the population
participates.3 Survey4 a Survey b Survey c Census
d Census e Survey 5 a Survey b Census c Census
d Survey6 Survey
6 a
MonthPrincipal
($)Interest
($)Balance
owing ($)
1 130 000.00 866.67 129 779.30
2 129 779.30 865.20 129 557.12
3 129 557.12 863.71 129 333.47
4 129 333.47 862.22 129 108.32
5 129 108.32 860.72 128 881.67
6 128 881.67 859.21 128 653.51
7 128 653.51 857.69 128 423.83
8 128 423.83 856.16 128 192.62
9 128 192.62 854.62 127 959.87
10 127 959.87 853.07 127 725.56
11 127 725.56 851.50 127 489.70
12 127 489.70 849.93 127 252.26
b
MonthPrincipal
($)Interest
($)Balance
owing ($)
1 130 000.00 866.67 129 366.67
2 129 366.67 862.44 128 729.11
3 128 729.11 858.19 128 087.31
4 128 087.31 853.92 127 441.22
5 127 441.22 849.61 126 790.83
6 126 790.83 845.27 126 136.10
7 126 136.10 840.91 125 477.01
8 125 477.01 836.51 124 813.52
9 124 813.52 832.09 124 145.61
10 124 145.61 827.64 123 473.25
11 123 473.25 823.15 122 796.40
12 122 796.40 818.64 122 115.05
15.50Shar
e pr
ice
($)
Month
16.00
16.5017.00
1–Jan
1–Feb
1–M
ar
1–Apr
1–M
ay1–
Jun1–
Jul
1–Aug
1–Sep
t
1–Oct
1–Nov
1–Dec
3G➔
4A
Maths A Yr 12 - Answers Page 525 Wednesday, September 11, 2002 3:41 PM
526 A n s w e r san
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sExercise 4B — Samples and sampling1 80, 84, 70, 85, 79, 54, 56, 51, 81, 672 Range of answers3 Range of answers4 Should be three different sets of numbers.5 a Random sampling
b Judgemental samplingc Accessibility samplingd Systematic samplinge Stratified sampling
6 a Systematic b Stratified c Systematicd Random e Stratified
7 A8 C9 Year 7— nine, Year 8 — eleven, Year 9 — nine, Year
10 — eight, Year 11 — seven, Year 12 — six10 36 men and 24 women
11
12 4000 13 40014 a 10 000 b 25 000 c 366315 No — estimated population 20 00016 a 625 b 500 c 625 17 a 833 b 1000 c 882
d 905
10 Quick Questions 11 Census 2 Survey3 Census 4 Random sample5 Systematic sample 6 Stratified sample7 Cluster sample 8 Judgemental sample9 Quota sample 10 Random sample
Exercise 4C — Bias1 Check with your teacher.2 Check with your teacher.3 a Sample does not represent characteristics of
population.b No control over responsesc Unrepresentative sampled Abnormal conditionse Only extreme groups in sample
4 The decrease in the value of the Australian dollar compared with the American dollar is accentuated by the large scale on the y-axis. The decrease is actually only 2 cents. The scale on the x-axis is not uniform (9 May, 11 May, 12 May).
5 What type of university tests? What do the terms ‘consistently’, ‘majority’, ‘more effective’, ‘most other’ mean? No hard evidence has been provided to support the claim.
6 a There would be many more student drivers in Year 12 than in Year 11 — perhaps also some in Year 10.
b Students with part-time jobs are in lower year levels as well.
c Residents not at the neighbourhood watch meeting have been ignored.
d Other music students who play instruments and don’t belong to the choir have been excluded.
e The composition of cars in a shopping centre car park is not representative of the cars on the road.
f Females have been excluded.g Users of the local library would not reflect the
views of teenagers.
Investigation — Contingency tables from census data1 a 37.8% b 41.9%
c Part (a) compares the number of males in the retail trade with the total number of male workers, while in part (b) the comparison is with the total number in the retail trade.
d It would be easier to survey those in the retail trade rather than surveying the male population, as the former number is smaller than the second.
2 Choose another category to survey.3 Percentage of persons in agriculture, forestry and
fishing
= × 100%
= 4.2%4 Analyse data from the 2001 census.
Exercise 4D — Contingency tables
3 a 1000 b 75 c 96.7% d 60% 4 a 200 b 44 c 90.9% d 5.1%
e 94% f Check with your teacher.5 B 6 D 7 A
b i 96% ii 3.3% iii 4% iv 96.5%
Age Male Female
20–29 10 7
30–39 7 8
40–49 12 3
50–59 1 2
1 Test results
TotalAccurate Not accurate
With virus 98 2 100
Without virus 388 12 400
Total 486 14 500
2 Test results
TotalAccurate Not accurate
Telling truth 777 23 800
Telling lies 156 44 200
Total 933 67 1000
8 a Test results
TotalAccurateNot
accurate
Bags with prohibited items
48 2 50
Bags with no prohibited items
145 5 150
Total 193 7 200
324 3307 636 319-----------------------
Maths A Yr 12 - Answers Page 526 Wednesday, September 11, 2002 3:41 PM
A n s w e r s 527
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9 a ii b ii c ii10 a
b
c
d
e 1.7%f 52.5%g Survey a sample of those in education rather than
conducting a survey on a sample of females as the total education group is fewer in number than the total female group.
11 a
b
c
d
e 10.6%f 65.9%g Same as g in question 10. Comments should note
increases in percentage and the reasons for this.
12 a
b i 35.8% ii 39.9%c No — more than 39% of the labour force are
female.13 a
b No — 33% of the males in the community were born overseas, while 49% of the people born overseas were male.
Exercise 4E — Applications of statistics and probability1 a Yes b 3 c Yes, both equal 3 d 32 a No b 5–9 and 20–24 c No
d 5–9 and 20–24 e 25–293 a b Yes
c 0 and 5 d Yes, both equal 2.5e 0
4 a 2 b 2 c 55 a b 0.73
6 A7 a b No
c 151–200 and 201–250d 0.67e 0.17
8 a Chemistry is symmetrical.Maths is not symmetrical.
b Chemistry: mode = 41–50 and 81–90,Maths: mode = 71–80
c Maths, because there are more scores further away from the centre of the distribution.
Male Female
Education 3 685 4 071
Other 239 389 240 029
Male Female Total
Education 3 685 4 071 7 756
Other 239 389 240 029 479 418
Total 243 074 244 100 487 174
Male Female
Education 1.5% 1.7%
Other 98.5% 98.3%
Total 100% 100%
Male Female Total
Education 47.5% 52.5% 100%
Other 49.9% 50.1% 100%
Male Female
Education 184 287 355 776
Other 4 087 764 3 008 492
Male Female Total
Education 184 287 355 776 540 063
Other 4 087 764 3 008 492 7 096 256
Total 4 272 051 3 364 268 7 636 319
Male Female
Education 4.3% 10.6%
Other 95.7% 89.4%
Total 100% 100%
Male Female Total
Education 34.1% 65.9% 100%
Other 57.6% 42.4% 100%
Male Female Total
In 2641 1752 4393
Not in 1728 3144 4872
Total 4369 4896 9625
Male Female Total
Aust. 4066 4468 8534
Overseas 2061 2156 4217
Total 6127 6624 12 751
Freq
uenc
y
Number of goals
0123456
0 1 2 3 4 5
21–3011–20
31–40
Freq
uenc
y
41–5051–60
Number of goals
05
10152025
51–1001–50
101–150
Freq
uenc
y
151–200
201–250
Number of people
02468
10
4B➔
4E
Maths A Yr 12 - Answers Page 527 Wednesday, September 11, 2002 3:41 PM
528
A n s w e r s
answ
ers
d
Yes, both 0.275
e
Mathematics
f
P
(>90% Chem)
=
0.05
P
(>90% Maths)
=
0.1
9
157
10
31.8, or 32 visitors
11 a
7
b
18.3
12 a
Lines vary.
b
Factory 1 is cheaper at $43.21 (compared to Factory 2 at $56.61).
c
Factory 2 is cheaper at $168.16 (compared to Factory 1 at $216).
d
Factory 2 is marginally more linear.
Investigation — Modelling Olympic Games times
1
Scatterplot
2
Line of best fit
3
Prediction
The line of best fit predicts a time of 9.5 seconds in the year 2035. The Olympic Games closest to this year is 2036.
Investigation — The door game
Part 11
1
P(winning if stay) =
P(winning if change mind) =
If you change your mind you will double your change of winning from 1 in 3 to 2 in 3.
10 Quick Questions 2
1
23.3
2
21.5
3
16
4
29
5
5
6
7.93
7
No
8
Yes, 45 is an outlier.
9
Median, because the outlier inflates the mean.
10
The outlier makes the range very large.
Chapter review
1 a
Survey
b
Census
c
Census
d
Survey
2
D
3
Random sample — where the participants are chosen by luck.Stratified sample — where the participants are chosen in proportion to the entire population.
Systematic sample — where a system is used to select the participants.Accessibility sample — where those within easy access form the sample.Quota sample — where a quota is placed on the number in the sample.Judgemental sampling — where a judgement is made regarding those who should form the sample.Cluster sampling — where the sample is selected from clusters within the population.Capture–recapture sampling — used mainly to estimate populations in wildlife where an initial sample is tagged then another sample selected from the whole population.
4 a
Systematic
b
Random
c
Stratified
5
Check with your teacher.
6
Year 7 — 12, Year 8 — 12, Year 9 — 11, Year 10 — 10, Year 11 — 8, Year 12 — 7
7
2000
8
750
9 a
Barry — 2667 Viet — 1667 Mustafa — 1571
b
1968
10
B
11
1984
12
Check with your teacher.
15 a
140
b
30
c
90%
d
10%
16 a
130
b
33.8%
c
97.5%
17
A
18 a
200
b
96%
c
34
d
93 %
e
93%
19 a
9.7%
b
8.0%
c
No significant difference
20
B
21 a
b
Secondary students were much keener on having more holidays than were primary students.
22 a
Yes
b
Both are 17.5.
c
17 and 18
d
17 and 18
13---
23---
13 Test results
TotalAccurate Not accurate
With virus
48 2 50
Without virus
149 1 150
Total
197 3 200
14 Test results
TotalAccurate Not accurate
Telling truth
77 3 80
Telling lies
17 3 20
Total
94 6 100
Attitude Primary Secondary
Fewer
7.5% 4.3%
Same
43.3% 19.1%
More
49.2% 76.6%
Total
100% 100%
13---
A n s w e r s 529
answ
ers
23 a b No
c 0.1524 a A variety of answers
b 131
CHAPTER 5 NavigationSkills check1 Lines of latitude run parallel to the equator. Lines of
longitude run from one pole to the other and are east or west of Greenwich.
2 0° 3 0° 4 Latitude 5 C = 2πr
6 40 030 km 7 Tangent =
8 Speed =
9 The time at the prime meridian (0° longitude)10 A triangle which has 2 sides congruent, and base
angles congruent
Exercise 5A — Review of Earth geometry1 a (30°N, 60°W) b (40°S, 20°W)
c (30°S, 50°E) d (40°N, 60°W)e (20°N, 20°W) f (30°S, 20°E)
2 Any 2 meridians; for example, NDS, NGS; or any line of longitude; for example, 20°W
3 a 40° b 30°c 10° d 60°
4 a Johannesburg b Shanghaic Montreal d Perth
5 a (35°N, 118°W) b (35°S, 20°E)c (0°, 100°E) d (38°N, 115°E)
6 a 4448 km b 7784 kmc 6672 km d 7339 km
7 a 7784 km b 6450 km8 4226 km
Exercise 5B — Accurate position description1 a 27°9.6′S, 153°36′E b 27°S, 153°45.9′E
c 27°S, 153°36′E d 27°0.9′S, 153°37.6′Ee 27°1.1′S, 153°33.6′E f 27°8′S, 153°44.5′E
2 Sketch3 a Mt Sydney b Black Island
c Pinnacle Point4 a 20°2.2′S, 148°52.7′E b 20°4.3′S, 148°58.3′E
c 20°4.8′S, 148°52.2′E d 20°10′S, 148°53.6′Ee 20°10.5′S, 148°55′E
Exercise 5C — The nautical mile and the knot1 a 120′ b 150′ c 1422′ d 2871.7′2 a 9°43′ b 39°8.7′3 a 17°17′ b 57.3′
4 a J, D b A, H c H, Id i 50°N, 80°E ii 0°, 0° iii 60°S, 0°
iv 0°, 30°W v 50°N, 0°e i 2400 n mile ii 2400 n mile iii 5400 n mile
iv 9000 n mile v 9000 n milef i 6600 n mile ii 6600 n mileg i 3600 n mile ii 3600 n mile iii 3000 n mile
5 a 1650 n mile b 3750 n milec 7050 n mile d 1110 n mile
6 8 knots7 a 3.5 knots b 6.5 km/h8 a 3.85 knots b 12.6 knots
c 289 n mile d 52.1 n milee 30 hours f 10 minutes
9 a 7872 hoursb 6.4 km/h, 3.4 knots
10 a 3600 n mileb ii 3600 n mile
ii The Earth is a sphere and any arc joining 2 points on its surface subtending an angle of 60° must be separated by the same distance.
c 200 hours11 a 570 n mile b 4.63 knots12 3.08 am13 A separation of 1′ near the equator on a line of
latitude is greater than that further from the equator.
10 Quick Questions 11 Latitude 2 Latitude 3 60′4 1852 metres 5 150 n mile
6 Speed = 7 The knot
8 6 knots 9 5400 n mile 10 5 pm
Investigation — Distance to the horizon1 Angle PHC = 90° (PH is a tangent to the circle, so CH
is perpendicular to PH.)2 PC2 = CH2 + HP2 (by Pythagoras’ theorem)3 CH = AC (Both are radii of the Earth;
both = 6371 km.)4 a 25.2 km b 79.8 km c 112.9 km d 357.1 km5 As height increases, distance also increases. (On a flat
Earth, distance to horizon would be greater.)
Exercise 5D — Using the compass1 a 128°C b 292°C c 193°C d 40°C2 291°T 3 6°E4 a 120°C b 226°C c 4°W d 257°29′T
Exercise 5E — Compass bearings and reverse bearings1 a 50°T b 300°T c 230°T d 145°T2 a 230°T b 120°T c 50°T d 325°T5 a 6 n mile b 5 n mile c 11.2 n mile
d 11.4 n mile e 15.7 n mile f 10.9 n mile6 b 12 knots7 a 187°T b 176°C c 50 min d 356°C8 a Great Keppel Is. b North Keppel Is.9 a (23°5.6′S, 150°54′E) b (23°13′S, 150°58.2′E)
10 a 56°T b 46°Cc 7.2 n miles d 54 minutes
11 a 304°(C) , 1.8 n mile b 271°(C), 8.2 n milec 328°(C), 7 n mile d 296°(C), 11.5 n mile
Freq
uenc
y
Class centre
02468
1012
1 2 3 4 5 6
oppositeadjacent--------------------
distancetime
-------------------
distancetime
-------------------
5A➔
5E
Maths A Yr 12 - Answers Page 529 Wednesday, September 11, 2002 3:41 PM
Exercise 5F — Fixing position1 a Check with your teacher.
b 155°T c 7.5 n miled 15 knots e 3.5 n mile
2 a Check with your teacher.b 9.3 n mile c 18.6 knots
3 a 131°T, 18°T, 299°T b 198°T, 340°T, 265°Tc 11 knots d A 219°, B 293°, C 254°
4 a Tower 53°, Antenna 88°5 b 14 n mile c 14 n mile d 19.8 n mile
e i 243° ii 252°6 b 56 n mile c 250°
Exercise 5G — Come to the rescue!1 Man and Wife Rocks 108°T; Miall Island 220°T2 plot 3 9.4 n mile 4 28 minutes5 3.48 pm6 Vessel has moved 1.75 n mile out to sea to 23°6.3′S,
150°59′E7 2.5 n miles to the east8 The wind had greater impact on pushing the boat than
it did on the swimmer.
Exercise 5H — Transit fix1 b i 6 n mile ii 5.6 n mile iii 5.3 n mile
c Plot d 20 knots2 c B 250°, D 291°, E 316°3 b 7.5 n mile
Exercise 5I — Running fix1 b 6 n mile2 b 197°
Exercise 5J — Doubling the angle on the bow1 a i 50° ii 130° iii 80° iv 3 n mile
b i 100° ii 40° iii 7 n milec i 42° ii 96° iii 84° iv 11 n miled i 130° ii 25° iii 6.5 n mile iv 45°Te i 45° ii 90° iii 45° iv 10 n milef i 20° ii 140° iii 20° iv 8 n mile
v 8 n mile2 a 25° b 5 n mile3 b At 1300, 30°; at 1330, 60°
c 9 n mile d 9 n mile4 b 8 n mile c 6.2 n mile (from sketch)
d 7.03 am e 100°
10 Quick Questions 31 Two 2 Cocked hat 3 Transit line4 Isosceles 5 Front6 Angle on the bow7 9 knots 8 4 hours9 84 n miles 10 One
Exercise 5K — Dead reckoning1 a Check with your teacher.
b 20°08.3′S, 148°59.7′Ec Check with your teacher.d iii 20°07.3′S, 149°01.5′E
iii 20°06.3′S, 149°03.3′Eiii 20°05.3′S, 149°04.9′E
2 a 20°07.3′S, 149°14′Eb 20°00.2′S, 149°07′Ec 20°05.2′S, 149°09.2′Ed 20°01.4′S, 149°07.3′E
3 a 3.8 n mile b 11.4 knotsc ii 20°05.4′S, 149°04.2′E
ii 20°03.3′S, 149°01′E
Exercise 5L — The lighthouse and navigation1 a AB = 10.5 m b 1908 m
c 1°48′ d 1.345 n mile2 a 4 short flashes of light followed by a long period
of darkness every 20 secondsc 3105 m
3 a 2 flashes, then darkness every 12 secondsc 5156 m f 7.6 n mileg i 0.48° ii 0.36°
4 b 6875 m d 0.68°
Exercise 5M — Let’s go cruising1 a 11°18′ east b 11° east2 a 27°30.9′S, 153°20.7′E b 27°30.1′S, 153°22.4′E
c 27°32.7′S, 153°25.2′E d 27°30.6′S, 153°17.3′Ee 27°34.8′S, 153°21.6′E
3 a Coochiemudlo Island b The Bluffc Submerged rocks d Myora Light
4 a i 308° ii 338° iii 0° iv 266°b i 297° ii 327° iii 349° iv 255°c iii 5.1 n mile iii 5.1 n mile
iii 4.8 n mile iv 2.6 n mile5 a iii Yellow light flashes every 2.5 seconds
iii Red every 4 secondsiii Green every 6 seconds
b So that they can be readily identified as different from neighbouring lights.
6 a 5 n miles b 150°T, 139°Cc 33 minutes d 10.58 ame A southwest wind could push the vessel towards
the rocks near Goat Island.7 Approx. 15 n mile, so approx. 160 litres.8 a 351°T, 227°T b 27°32.8′S, 153°21.6′E
Exercise 5N — Air navigation1 a 26°15′S, 151°56′E b 26°40′S, 152°00′E
c 26°·17′S, 152°41′E d 26°33′S, 151°51′E2 a Tansey b The Bluff c Abbeywood3 a 1998 b 2457 c 20434 a 350°T, 339.5°C b 05°T, 355°C5 a 149°30′C
b Barambah Ck, Clonya, Murgon, Nanango.
Maths A Yr 12 - Answers Page 530 Wednesday, September 11, 2002 3:41 PM
A n s w e r s 531
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Chapter review1 a A, 30°N, 60°W; B, 40°S, 20°W; C, 30°S, 50°E;
D, 40°N, 60°Wb NDS, NGS, NHS or any line of longitude (for
example, 40°W)c Fd PG, PN, PH, PC etc.
2 a 20°2.2′S, 148°52.7′Eb 20°10′S, 148°53.7′E
3 a 5400 n mile b 10 800 n milec 4200 n mile d 7920 n mile
4 a 1080 n mile b 5340 n mile5 a 360′ b 1110′ c 1695′ d 3457.4′6 540 n mile, 1000 km7 a 6 knots b 13.3 knots c 522 n mile
d 198.3 n mile e 50 hours f 15 minutes8 6 hours 24 minutes9 a 400 n mile b 180°T
c 5 hours d 6.45 pm10 a 114°C b 253°C
c 6°W d 206°T11 286°T12 b 9.8 n mile c 29.4 knots d 48°T13 a = 55°, b = 125°, c = 70°, PR = 7.4 n mile14 a 18° b 36°
c 13 n mile d 13 n mile15 b 50°, 100° c 12 n mile d 12 n mile16 a 5.57 m b 65.8 m
c 1.68° d 5810 m17 a 3 short flashes then long period of darkness every
16 secondsb 130 m c 16 n mile d 2480 m
18 a 8.1 n mile b 8°Tc Approx. 1 h 20 min trip, ETA 8.20 am
19 a 240°T b 16.5 n milec Plot d 11.45 am
CHAPTER 6 Land measurementSkills check1 Millimetre, centimetre, metre, kilometre2 Perimeter3 a 24 cm b 30 m c 15.6 cm
d 16.8 m e 12.6 m f 36.0 mg 38 m
4 a l2 b l × w c πr2
d b × h × e l × h5 a 1.5 cm b 0.18 m c 12 300 cm
d 680 m e 12 500 m6 a 40.7 m2 b 435.8 m2 c 51.7 m2
d 177 m2 e 25 m2
7 a 0.9397 b 0.9659 c 0.32498 c2 = b2 + a2
9 a 5 cm b 8 cm c 9.6 m
10 a b
c
11 Sine = Cosine =
Tangent =
12 a 6.8 cm b 7.7 m c 65.0 m
Exercise 6A — Perimeters and areas of triangles1 a 1.73 cm b 23.1 m c 11.4 m2 a 1.73 cm2 b 277 m2 c 55.3 m2
3 a 12.5 m2 b 4.5 m2
c 7443 m2 d 118.2 m2
4 a 26 m, 13 m b 90.9 m, 45.45 mc 42.4 km, 21.2 km
5 a 27.9 m2 b 250 m2 c 52.4 km2
Exercise 6B — Perimeters and areas of polygons1 a 5797 m2 b 1062 m2 c 27 952 m2
2 a 97.4 m2 b 3195 m2
3 Approx. 36 ha
Exercise 6C — Surveying on level ground without obstacles1 a 32 m b 28 m c 59 m
d 73 m e 47 m2 a 86.3 m b 107.5 m c 47.4 m
d 49.0 m3 Sketch4 a 120 m b 5
c i 48 m ii 39 m iii 37 m iv 32 m v 35 md i 65.8 m ii 44.7 m iii 34.4 m iv 90.2 me i 43.15° ii 1014 m2 iii 81.2°f Sketchg AB survey line established and measured. Staffs at
features Z and C, measurements taken. Staffs at V and D, measurements taken.
h 2340 m2
10 Quick Questions 11 5.47 m 2 × a × b × sin C
3 48.5 m2, 196.6 m2 45 24.2 m2 6 AB7 KF, JE, ID, HC8 36 m, 59 m, 73 m, 32 m, 84 m9 240 m2
Maths A Yr 12 - Answers Page 531 Wednesday, September 11, 2002 3:41 PM
532 A n s w e r san
swer
sExercise 6D — Surveying around obstacles1 a 42 m b 31 m c 52 m2 Sketch3 a Sketch
b The distance between the second and third staffs placed by Peter.
Exercise 6E — Plane table surveying: intersection or triangulation1 a 61 m
b i 43 m ii 28 m iii 106 m iv 124 mc i 065° ii 310° iii 180° iv 150°d 301 m e 0.38 ha
2 a 59 mb ii 28.5 m ii 31.5 m iii 32 m iv 73 m
v 49 mc 0.25 had i 15° ii 81° iii 151°
3 a 83 m b $1328 c 450 m2
4 a Sketchb i 100 m ii 66 m iii 50 m iv 90 m v 86 mc i 270° ii 310° iii 240°d 4300 m2
Exercise 6F — Plane table surveying: radiation and traversing1 a i 25 m ii 35 m iii 30.5 m iv 51.5 m
b i 0° ii 070° iii 180°c 1900 m2
2 a ii 23 m ii 72 m iii 51 m iv 12.5 mv 104 m vi 109 m vii 75 m
b 0.31 ha3 a Radiation b sketch
c A, 123°; B, 136°; C, 152°; D, 180°.d 3160 m2
4 a Sketch b traversingc i 212° ii 270°d i 107 m ii 77 m e 3800 m2
10 Quick Questions 21 Offset and triangulation2 41 m, 10 m3 Intersection (or triangulation), radiation, traversing4 Intersection5 Radiation6 Traversing7 287.5 mm8 4 triangles9 Area = = 310 m2
10 10 m2
Exercise 6G — Levelling: vertical measurements in relation to a datum1 a i 50.00 m ii 51.69 m
b 1.94 m c 53.63 md
2 a i 3.60 m ii 2.80 m iii 53.60 m iv 50.00 mb 50.80 m
3 a 61.25 m b 61.25 m c 61.25 md 61.25 m e 60.00 m f 59.50 mg 58.75 m h 58.25 m i 5.00 mj 10.00 m k 15.00 m
Exercise 6H — Topographic maps1 Easting 84, northing 462 a Maculata Park b oval
c building at quarry3 a GR 871464 b GR 854487
c GR 8134884 a 3350 m b 1250 m5 a 352° b 090°6 a Abattoirs, bridge over river on Warrego Highway,
then along river and over slag heapsb 155°. Yes. A scale diagram could be sketched and
trigonometry used to calculate angles.
Exercise 6I — Contour maps1 a 10 m b 80 m c 50 m
d Up a hill then down a steep descent, then up and down another smaller hill.
e Sketch f 52 a 93 m b 68 m3 a 20 m b 10.3 km c Sketch
d 20 e 293°f No, not if X and Y are at the surface.
4 a b 16.4°, steep
5 a 45° b 18.4° c 0.57°d 1.15° e 2.97°
6 a 1.27°
Exercise 6J — Cadastral maps and site plans1 a 630 m2 b 23.0 × 27.499 m
c 632.477 m2 d 1 : 1500e Rectangle of length 60 mm and width 42 mmf ii $57.88/m2 ii 850 m2
g ii Lot 109ii location, elevation, road frontage size, views
2 a 2100 m2, 83 perchesb 103.68 m2 c 56.3 md 0.049 or approx. e i rising ii 1800 mm iii 1.375°
Exercise 6K — Orienteering1 a 8° b 137° c 222° d 45°2 a 67 m b 136 m c 77 m d 130 m3 Any suitable set of 8 instructions.
Chapter review1 a 126 m2 b 165 m2 c 516 m2
d 2325 m2 e 8850 m2
2 0.2 ha3 a ii 150 m ii 52 m iii 63.2 m iv 13 m
v 75 m vi 141.9 mb ii 936 m2 ii 1533 m2 iii 4500 m2
iv 5912.5 m2
4 Sketch
Sta. BS IS FS HI RL Dist. Notes
A 3.63 53.63 50.00 0.00 TBM
B 1.94 53.63 51.69 20.00
S S a–( ) S b–( ) S c–( )
13.41----------
120------
Maths A Yr 12 - Answers Page 532 Wednesday, September 11, 2002 3:41 PM
A n s w e r s 533
answ
ers
5 a 84 mb i 050° ii 115° iii 295° iv 238° v 090°c 2000 m2 d 190 m
6 a i 43 m ii 48 m iii 46 m iv 56 m v 86 mb i 051° ii 090° iii 253°c 3200 m2
7 a i 3.90 m ii 2.70 m iii 53.60 m iv 50.00 mb 50.90 c Sketch
8 a i Industrial Estate ii Finlay Islandb 2.5 km c 153°
9 a 250 b 1 in 5c 11.3°, steep to moderate
10 a 45° b 26.6° c 1.1°d 2.9° e 7.2°
11 1012 a 90 m b 20 m c Sketch13 a 630 m2 b Sketch
CHAPTER 7 NetworksExercise 7A — Networks, nodes and arcs1 a ABDE b ABCE2 a b 487 km c 254 km
d i ii 357 min iii 191 min
iv
v
3 a 185 km b ii ii 321 min iii 143 min
c
d
4 a b $3.30 c $3.80
5 C
History of mathematics1 Men of Mathematics by E. T. Bell.2 The Nobel Prize and the Leroy P. Steele Prize.3 An algorithm is a procedure for solving a problem by
a number of steps.
Exercise 7B — Minimal spanning trees1 a b
c d
2 a Sturt b Rockdale c To Sturtd
Ulawatu Yallingup Black Rock Angourie Bargara
Ulawatu 0 120 100 209 254
Yallingup 120 0 220 118 160
Black Rock 100 220 0 109 154
Angourie 209 118 109 0 45
Bargara 254 160 154 45 0
Ulawatu Yallingup Black Rock Angourie Bargara
Ulawatu 0 85 75 157 191
Yallingup 85 0 160 80 114
Black Rock 75 160 0 82 116
Angourie 157 80 82 0 34
Bargara 191 114 116 34 0
U1
Ya
BR An
Ba100
120
109
118
45
160
U1
Ya
An
Ba
BR
75
85
82
80
34
120
Re
Mo
Pi
VG
Ma
Ga
Ce
75
4734
28
59
20
38
40
64
25
45
Re Pi Mo Ce VG Ma Ga
Re 0 62 58 104 108 147 179
Pi 62 0 41 65 46 85 123
Mo 58 41 0 46 76 126 121
Ce 104 65 46 0 30 90 75
VG 108 46 76 30 0 60 98
Ma 147 85 126 90 60 0 38
Ga 179 123 121 75 98 38 0
Re Pi Mo Ce VG Ma Ga
Re 0 47 44 84 81 119 143
Pi 47 0 25 45 34 75 100
Mo 44 25 0 40 59 97 99
Ce 84 45 40 0 20 58 59
VG 81 34 60 20 0 38 66
Ma 119 72 97 58 38 0 28
Ga 143 104 99 59 28 28 0
L
P B
T
K
2.401.50
1.50 1.80
1.80 2.00
2.40
A
B
D
C
4
5
8A
B
C
D
4
5
4
A D
B
C
E
17
15
12
18
A D
B
C
E
30
15
20
15
Yule
Zenith
Rockdale
Urchin
Walga
Xavier
View
PallasSturt
5052
67
52
55
5042
50
6D➔
7B
Maths A Yr 12 - Answers Page 533 Wednesday, September 11, 2002 3:41 PM
534 A n s w e r san
swer
s3 a 585 m b 245 m
c Check with your teacher.4 a b
c d
5 a
b
c
6 53 km7 54 km8 a 68 km b $1.7 million9 a $215 b $1740
10 B 11 D
Exercise 7C — Shortest paths1 a 20 b 38 c 74
d 45 e 28 f 1392 a 165 km b 202 km c 202 km3 a 37 b 90 c 32
d 72 e 30 f 444 a
b 80 min
10 Quick Questions 11 6 2 9
3 1 4
5 AC, AD, DF, CF 6 $16 6007 D–C–E–F 8
9 $16 200 10 B–A–C
Exercise 7D — Network flow1 a
b
c
d
234
5 a
b
E
D
C
A
B
F
20
2324
18
18
FDB
ECA
45 45
48 48
45
A B
C D E
F G40
50
23 2320 20
A B
C
E
D
F64
67
6
AD
F
B
E
C
G
17 15
15
12
10
13
E
F
G
DA
CB
12 1017
8
1510
C A
E
D G K
BA I
H
J
5 5
5
8 85 5
55
85
B
A
C
E
D
70
30
50
20
25
60
3025
a 23 b 16 c 16
a 6 b 3 c 3a i 250 ii No b i 150 ii Yesc i 24 ii Yes d i 15 ii No
From To Flow capacity
A B 4
A C 5
A D 3
B E 3
C B 2
C E 4
D C 2
D E 6
From To Flow capacity
A B 4
A C 5
A D 3
B E 3
B C 2
C E 4
D C 2
D E 6
A B CDE F
A BC E F
100
50200
250 300
A B
D EC
50100
E
250 200 100S T UR
20
20
Q
15 12
125
10
O
M
R
N E
8
83
F2
8
86
5D
H
G J
E
Maths A Yr 12 - Answers Page 534 Wednesday, September 11, 2002 3:41 PM
Float (B) = 10, Float (C) = 1, Float (F) = 1c Activity B can be delayed 10 minutes, activity C
can be delayed 1 minute, activity E can be delayed 1 minute, activity F can be delayed 1 minute, activity H can be delayed 1 minute, activity J can be delayed 3 minutes.
e Although few patients were tested, it appearsthat a greater percentage (80%) of those givena large dose of the drug recovered, whereasa much smaller percentage (29%) of those notgiven the drug recovered. 20% of people testedwere given a large dose of the drug andrecovered, 15% of people tested were given asmall dose and recovered, whereas only 10%of people were not given the drug and recovered.So it could be said that a patient is more likelyto recover if the drug is taken.
Exercise 9B — Compound events — mutually exclusive events1 a, d, e, g2
3
4 = 0.517
5 D
6 a = = b
7 a = b = c =
8 a 0.258 b 0.449 c 0.8659 a 0.037 b 0.296 c 0.667 d 0.333
10 a 0.32 b 0.46 c 0.3111 a 0.4999 b 0.9997 c 649 773
Exercise 9C — Compound events — Venn diagrams1
2 a = 0.275 b 0.4
a 0.2646 b 0.0204 c 0.1764
a b c d
436------ 1
9---
636------ 1
6---
18--- 3
8--- 7
8--- 3
8---
16--- 1
6--- 1
6--- 1
216---------
New York up
New York down
Tokyo up
Tokyo up
Tokyo down
Tokyo down
Australia up
Australia up
Australia up
Australia up
Australia down
Australia down
Australia down
Australia down
0.7 × 0.45 × 0.5 = 0.16
0.7 × 0.45 × 0.5 = 0.16
0.7 × 0.55 × 0.5 = 0.19
0.7 × 0.55 × 0.5 = 0.19
0.3 × 0.45 × 0.5 = 0.07
0.3 × 0.45 × 0.5 = 0.07
0.3 × 0.55 × 0.5 = 0.08
0.3 × 0.55 × 0.5 = 0.08
0.55 × 0.55 = 0.3025
0.55 × 0.45 = 0.2475
0.45 × 0.55 = 0.2475
0.45 × 0.45 = 0.2025
H
H
T
H
T
HH
HT
TH
TT
0.550.450.55
0.45
0.55
0.45T
H
H
T
H
T
H
TH
T
TH
T
T
H
P(H, H, H) =
P(H, H, T) =
P(H, T, H) =
P(H, T, T) =
P(T, H, H) =
P(T, H, T) =
P(T, T, H) =
P(T, T, T) =
1—81—81—81—81—81—81—81—8
0.6 x 0.2 = 0.12
0.6 x 0.8 = 0.48
0.4 x 0.2 = 0.08
0.4 x 0.8 = 0.32
W
B
B'
B
B'
WB
WB'
MB
MB'
0.60.80.2
0.8
0.2
0.4M
a = b c
a b = c d e 1
a 4 b 5 c 8
P
T
S
0.4 x 0.3 = 0.120.4 x 0.25 = 0.100.4 x 0.45 = 0.18
PBPFPL
B
LF
0.25 x 0.3 = 0.0750.25 x 0.25 = 0.0630.25 x 0.45 = 0.112
SBSFSL
B
LF
0.35 x 0.3 = 0.1050.35 x 0.25 = 0.0880.35 x 0.45 = 0.157
TBTFTL
B
LF
1440------
1640------
1040------
0.35 x 0.286 = 0.10
0.35 x 0.714 = 0.250.40 x 0.375 = 0.15
0.40 x 0.625 = 0.250.25 x 0.80 = 0.20
0.25 x 0.20 = 0.05
N
NR
NR'SR
SR'LR
LR'
R
R'
L
SR
R'
R
R'
452------ 1
13------ 6
13------ 15
52------
1645------ 35
45------ 7
9--- 29
45------ 19
45------
16 76+178
------------------
59 13+148
------------------ 72148--------- 18
37------ 19
37------
1236------ 1
3--- 24
36------ 2
3--- 15
36------ 5
12------
317 o'clock 11 o'clock
5580 34
S55
200---------
Maths A Yr 12 - Answers Page 540 Wednesday, September 11, 2002 3:41 PM
A n s w e r s
541
answ
ers
3
The events are mutually exclusive and the Venn diagram could have been drawn as two circles which did not overlap.
4
0.18
5
0.9009
6
C
78
0.27, much higher probabilities of winning with roulette.
9
36
10
9
10 Quick Questions 1
1 2 3
0.36 or 36%
4
0.16 or 16%
5
0.48 or 48%
6
7 8
4
9
14
10
Exercise 9D — The binomial distribution using Pascal’s triangle
1 a
1 7 21 35 35 21 7 1
b
1 9 36 84 126 84 36 9 1
2 a
1 5 10 10 5 1
b
1 7 21 35 35 21 7 1
3 a
1
b
4
c
70
d
1
e
110
4 a
0.0256
b
0.1176
c
0.125
d
0.0132
e
0.0720
f
0.0156
5 a
0.0179
b
0.0284
c
0.3456
6 a
0.2344
b
0.3125
7 a
0.2322
b
0.8936
8 a
0.4019
b
0.8038
9 a
0.5
b
0.2734
10 a
0.5
b
(0.5)
10
11 a
0.25
b
(0.75)
6
c
0.0330
12 a
0.2090
b
0.0413
13
0.1342
Career profile — Gail Twemlow
1
Selling betting tickets, calculating dividends, Cashbook and basic accounting
2
A boxed trifecta is more expensive because you have more chances of winning.
3
Reading cashbooks and using computer screens to follow what money has gone through the system.
Investigation — Pascal’s triangle
1
2
The triangle is symmetrical about a vertical line through the centre.
3
Number of entries in row
=
row number
+
1
4
Odd-numbered rows have an even number of entries.Even-numbered rows have an odd number of entries.
5
An odd number of trials has two middle numbers of the same value.An even number of trials has one middle number.
6
Sum of numbers in row
=
2
row number
(2 to the power of the row number)
7
Yes. 11
3
=
1331Yes. 11
4
=
14 641
8
They are square numbers.
9
Fibonacci’s sequence
10
Use the diagonal1
36
1015
11
The triangular numbers are ocated in the diagonal shown in question 10.
12
Sum of 10 lies in the position below the 4 to the right. This pattern continues. The same pattern continues for the numbers in the second diagonal.
a
37%
b
63%
IPT 16TS
031 29
S
S 0.51A
0.180.08 0.23
S
A 0.9009B
0.00090.0291
0.0691
S
A14
46
7
302
C
B
S 103
8
9
5
84
N
C
16--- 1
6---
126------
713------
120------
1 Row 0
1
1
11
1
11
1
1
1 10 45 120 210 252 210 120 45
9 36 84 126 126 84 36
8 28 56 70 56 28
7 21 35 35 216 15 20 15 6
5 10 10
4 63 3
4
5
7
8
9
10
1
121
1
1
11
1
11
Row 1Row 2
Row 3
1
1
1
11
1
11
1
11 10 45 120 210 252 210 120 45
9 36 84 126 126 84 36
8 28 56 70 56 28
7 21 35 35 216 15 20 15 6
5 10 10
4 63 3
4
5
7
8
910
1
121
1
1
11 2
3 5
11
1
11
2113
89
34
8
55
1 + 3 = 4 = 22
3 + 6 = 9 = 32
6 + 10 = 16 = 42
9B
➔
9D
542 A n s w e r san
swer
s13
s = 2r + 1 − 114 a Multiples of 2
b Multiples of 3
History of mathematics — Blaise Pascal1 16 years old2 A calculating machine3 The Puy de Dôme mountain4 For probability, permutations and combinations5 A brain tumour and stomach ulcer
Exercise 9E — Binomial probabilities through tables1 a 0.0008 b 0.9527 c 0.5793 d 0.99072 a 0.8281 b 0.9389 c 0.9887 d 0.95323 a 0.5000 b 0.6964 c 0.4142 d 0.00004 0.86845 a 0.6550 b Between 0.6167 and 0.96666 a 0.6230 b 0.5881 c 0.5000 d 0.0781
e 0.0139 f 0.00347 a 0.0404 b 0.9536 c 0.99408 a 0.2
b i 0.2013 ii 0.3222 iii 0.1074c The probability of this is very slight; there may
20 D21 a Two outcomes, success or failure, same event
repeatedb Tossing a coin 6 timesc Rolling a die and noting the upper-most face
22 a 0.402 b 0.03223 0.01624 a 0.39 b 0.39 c 0.7825 a 0.8725 b 0.804226 a 0.2 b 0.370427 a 0.12 b 0.2517
Row (r) 0 1 2 3 4 5 6
Sum (s) 1 3 7 15 31 63 127
Sum 2 3 4 5 6 7 8 9 10 11 12
Prob.
a 0.5 b c
13--- 1
3---
10
14---
16--- 5
6---
136------ 2
36------ 3
36------ 4
36------ 5
36------ 6
36------ 5
36------ 4
36------ 3
36------ 2
36------ 1
36------
12--- 2
9--- 1
9---
18--- 3
8---
1536------ 32
36------
2549------ 20
49------
2042------ 20
42------
0.05 0.25 0.25
A
S
B
18 12 13
Yes No
S
3043------
Maths A Yr 12 - Answers Page 542 Wednesday, September 11, 2002 3:41 PM
A n s w e r s 543
answ
ers
CHAPTER 10 The normal distribution and games of chanceSkills check1 Answers will vary. Check with your teacher.2 a 6.7 b 2.4 c 0.4 below the mean3 Distribution b4 45 to 555 a the value of x is larger than 40
b the value of x is less than or equal to 40c The value of x is larger than 20 and less than 30.
Exercise 10A — z-scores1 32 −23 a 0 b 1 c −2 d 3 e −14 a 10.5 b 13.7 c 16.9 d 7.3 e 0.95 −0.276 1.57 a −0.48 b 1.44 c 0.08 d −2.24 e 2.88 a 10.3 s b 10.58 s c 10.37 s
d 9.88 s e 10.251 s f 10.524 s9 a = 19.55, sn = 1.76 b 1.68
b = 56, σn = 20.1c i 0.30 ii 2.2 iii −2.0
11 B12 B13 C14 a = 64.7, σn = 11.4
b Highest score z = 2.66, Lowest score z = −1.7315 English 1, Mathematics 1.31, Biology 1.5,
Computing studies −2, Visual arts 0.67, Music −0.8
Exercise 10B — Comparison of scores1 a English 1.25, Maths 1.33
b Maths mark is better as it has a higher z-score.2 2nd test, Barbara’s z-score was −0.33 compared to
−0.5 in the first test.3 C4 D5 Course A, z-score of −0.8 compared to −0.75 on
course B6 a Atlanta 0.44, Sydney 1
b In Atlanta because of the lower z-score7 C8 B
9 a Mathematics = 59.5, sn = 17.9
Chemistry = 59.6, sn = 16.8b Mathematics 0.25, Chemistry 0.20. So
Mathematics is the better result.10 Kory is the better candidate with a z-score of 1.5
compared with 0.875 for Ricardo.
10 Quick Questions 11 22 −23 −1.034 2.955 One standard deviation above the mean6 Two standard deviations below the mean7 508 89 English 1.25, Maths 1.4
10 Maths
Exercise 10C — Distribution of scores1 a 68% b 95% c 99.7%2 a 68% b 95% c 99.7%3 95%4 16%5 a 68% b 16% c 0.15%6 21.1 and 33.97 a 68% of the values have a z-score between −1
and 1.b 95% of the values have a z-score between −2
and 2. c 99.7% of the values have a z-score between −3
and 3.8 B9 A
10 0.15%11 a 16% b 16%12 a 95% b 16% c 34%
d 15.85% e 83.85%13 a 95 g to 105 g b 92.5 g to 107.5 g14 163 cm − 181 cm15 Faulty, as the one chosen has a z-score greater than 316 2.6 kg − 5 kg
Exercise 10D — Standard normal tables1 a 0.8413 b 0.9192 c 0.9641
d 0.1587 e 0.0446 f 0.2417g 0.6826 h 0.9544 i 0.9974j 0.1359 k 0.0215 l 0.8664
2 a 0 b −0.75 c −1 d 1.53 a 0.5 b −0.5 c −1.3 d 1.24 a 0.8413 b 0.9452 c 0.5
d 0.0013 e 0.3413 f 0.81855 a 0.6406 b 0.8577 c 0.5 d 0.3594
e 0.2812 f 0.6188 g 0.0509 h 0.05546 a 0.0500 b 0.1335 c 0.0294 d 0.86657 a 0.7486 b 0.9082 c 0.2514 d 0.65688 a 75% b 37 c 469 a i 0.9332 ii 0.8413 iii 0.1210
b 22.6%10 a 0.7881 b 0.3446 c 0.1151
d 0.7881 e 0.5403
10 a Amount ($) Class centre Frequency
0–<20 $10 2
20–<40 $30 8
40–<60 $50 19
60–<80 $70 15
80–<100 $90 6
x
x
x
x
x
9E➔
10D
Maths A Yr 12 - Answers Page 543 Wednesday, September 11, 2002 3:41 PM
544 A n s w e r san
swer
s11 4.75%12 0.38%, assuming weights to be normally
distributed.
Exercise 10E — Odds1 a $105 b $105 c $429 d $300
e $15 f $33.33 g $66.662 a $140 b $175 c $507 d $420
e $60 f $83.33 g $216.66
3 a b c
d e f
4 a 2:1 b 4:1 c 3:2 on d 5:2e 7:5 f 2:1 on g 6:4 h 11:9
5 a Evens b 5:1 c 3:1d 12:1 e 3:1
6 a 2:1 b 3:1 c Evensd 7:5 e 2:1 on f 5:2 on
7 a $36 000 b i $13 500 ii $22 5008 a $160 b $71.11 c $80
Exercise 10F — Two-up1 2 3
4 5 6
7 a TH, TH, TH, TH b
8
9 a b c d e 0.48
10 Not quite, probability of winning = 0.48
Exercise 10G — Roulette1 a b
2 a 19:18 b 31:6c No, slightly lower
3 a $60 b 0 c $200 d $754 Nothing happens except when the ball lands on 0,
then he loses both bets.
Exercise 10H — Common fallacies in probability1 a 1/16 b 1/32 c 1/22 a i 0.32 ii 0.24
b Her chances of winning any match remain 0.75.4 a Events are not independent.