Chapter 3
3.1 9 or 10
3.2 10 or 11
3.3 a 7 to 9
3.5a
b
10
15
0.60
0.80
1.00
3.6 a
b
c The number of pages is bimodal and slightly positively skewed.
3.7 a
6
8
10
0.60
0.80
1.00
b
c
d The ages are bimodal and positively skewed.
3.8
10
15
0.60
0.80
1.00
10
15
3.9 a
b
c The histogram is positively skewed.
3.10 a
20
30
15
20
25
Stem & Leaf Display
Stems Leaves
30 ->0112222222356667777788
b
c The number of stores is bimodal and positively skewed.
3.11
3.12 a
0.80
1.00
10
15
20
10
15
20
b
c
3.13
0.60
0.80
1.00
40
60
80
3.14 a
b
c
10
15
20
25
0.80
1.00
1
2
3
4
A B C
Stem & Leaf Display
Stems Leaves
4 ->2445677789
3.15
3.16 a The histogram should contain 9 or 10 bins. We chose 10.
b
3.17
40
60
80
40
60
80
100
60
80
100
3.18
3.19
3.20
40
60
10
20
30
40
60
80
100
3.21
3.22
3.23a Interval
b
50
100
150
20
30
300
400
500
600
3.24
3.25
3.26
300
400
150
200
300
400
500
3.27
3.28
200
300
400
150
200
250
300
3.29
3.30
After a rapid increase the numbers have leveled off.
3.31a
2500.0
3000.0
60.0
70.0
80.0
b
2000
2500
3000
1000
1200
1400
3.32
The numbers of females and males are both increasing with the number of females increasing faster.
3.33
The number of property crime decreased slowly over the 15 years.
1400
1600
1800
2000
10000
12000
14000
3.34
The per capita number of property crimes decreased faster than did the absolute number of property crimes.
3.35a
5000
6000
12000
14000
16000
18000
b
The inflation-adjusted GDP grew at a moderate rate.
3.36
Until about four years ago consumption was increasing and production was falling. However, there appears to be a
change in both trends.
6000
7000
8000
20,000
25,000
3.37
3.38
\
500,000
600,000
700,000
3000.0
3500.0
4000.0
4500.0
b
Over the last 28 years both receipts and outlays increased rapidly. There was a five-year period where receipts were
higher than outlays. After 2004 the deficit increased precipitously.
3.39
0.0
500.0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31
-0.02
0
0.02
0.04
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31
3.40
The inflation adjusted deficits are just as bad.
3.41 The cost is calculated as follows.
-0.01
0
0.01
0.02
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31
800
1000
1200