D1 :H
0
Rejection region:
684.1ttt 39,05., =
13.104a
D0 :H
= 0
D1 :H
0
Rejection region:
345.1ttt 14,10., −=−=−
13.105
D0 :H
= 0
D1 :H
0
Rejection region:
or
014.2ttt 44,025.,2/ =
13.106
D0 :H
= 0
D1 :H
0
13.107
D0 :H
= 0
D1 :H
> 0
13.108
D0 :H
= 0
D1 :H
> 0
13.109
D0 :H
= 0
D1 :H
> 0
13.110 The matched pairs experiment reduced the variation caused by different drivers.
13.111
D0 :H
= 0
D1 :H
> 0
13.112 Salary offers and undergraduate GPA are not as strongly linked as are salary offers and MBA GPA.
13.113 a
D0 :H
= 0
D1 :H
0
Rejection region:
684.1ttt 41,05., −−=−
D0 :H
D1 :H
Rejection region:
660.1ttt 97,05., ==
13.114
D0 :H
= 0
D1 :H
> 0
t = 22.10, p-value = 0. There is enough evidence to infer that this generation is more educated than their fathers.
D0 :H
D1 :H
13.116
13.117
LCL = 28.18, UCL = 43.38
13.120 a
1/:H 2
2
2
10 =
1/:H 2
2
2
11
c The value of the test statistic is unchanged and in this exercise the conclusion changed as well..
13.121 a LCL =
21 ,,2/
2
2
2
1
F
1
s
s
=
03.4
1
19
28
= .366, UCL =
12 ,,2/
2
2
2
1F
s
s
=
03.4
19
28
= 5.939
13.122
1/:H 2
2
2
10 =
1/:H 2
2
2
11
13.123
1/:H 2
2
2
10 =
1/:H 2
2
2
11
1/:H 2
2
2
Rejection region:
72.3FFF
10,10,025.,,2/ 21
==
or
269.72.3/1F/1F/1FF 10,10,025.,,2/,,2/1 1221 ====−
F =
2
2
2
1s/s
= 193.67/60.00 = 3.23, p-value = .0784. There is not enough evidence to infer that the variances of the
marks differ between the two sections.
1/:H 2
2
2
10 =
2
2
2
1s/s
13.126
1/:H 2
2
2
10 =
1/:H 2
2
2
11
Rejection region:
48.1FFF
99,99,025.,,2/ 21
=
or
68.48.1/1F/1F/1FF 99,99,025.,,2/,,2/1 1221 ===−
F =
2
2
2
1s/s
= 41,309/19,850 = 2.08, p-value = .0003. There is enough evidence to conclude that the variances differ.
2
2
2
10 /:H
13.128
2
2
2
10 /:H
= 1
2
2
2
11 /:H
1
Rejection region:
39.1FFF 99,99,05.,,2/ 21 =
or
72.39.1/1F/1F/1FF 99,99,05.,,,,1 1221 ===−
a
+−
−
=
21
21
n
1
n
1
)p
ˆ
1(p
ˆ
)p
ˆ
p
ˆ
(
z
=
+−
−
100
1
100
1
)425.1(425.
)40.45(.
= .72, p-value = 2P(Z > .72) = 2(1 – .7642) = .4716.
+−
−
21
n
1
n
1
21
c The p-value decreases.
13.132 H0: (p1 – p2) = 0
H1: (p1 – p2) ≠ 0
c. The p-value decreases.
21
n
1
n
1
21
e. The p-value decreases.
c The interval widens.
13.134
)pp(:H 210 −
= 0
There is enough evidence to conclude that those who paid the regular price are more likely to buy an extended
warranty.
13.135
)pp(:H 210 −
= 0
13.136
)pp(:H 210 −
= 0
− )pp(:H 211
0
13.137a
)pp(:H 210 −
= 0
− )pp(:H 211
0
Rejection region:
05.
zzz =
= 1.645
b
)pp(:H 210 −
= .05
− )pp(:H 211
.05
Rejection region:
05.
zzz =
= 1.645
13.138
)pp(:H 210 −
= –.08
− )pp(:H 211
13.139
)pp(:H 210 −
= 0
− )pp(:H 211
0
13.140 a
)pp(:H 210 −
= 0
− )pp(:H 211
0
05.
zzz −=−
13.141 a
)pp(:H 210 −
= 0
− )pp(:H 211
0
Rejection region:
01.
zzz −=−
= –2.33
13.142
)pp(:H 210 −
= 0
− )pp(:H 211
0
Rejection region:
645.1zzz 05.==
13.143
)pp(:H 210 −
= 0
− )pp(:H 211
0
Rejection region:
01.
zzz −=−
= –2.33
13.144
)pp(:H 210 −
= 0
− )pp(:H 211
0
Rejection region:
645.1zzz 05.−=−=−
13.145
)pp(:H 210 −
= 0
− )pp(:H 211
0
Rejection region:
645.1zzz 05.==
13.146
)pp(:H 210 −
= 0
− )pp(:H 211
0
Rejection region:
645.1zzz 05.==
13.147
)pp(:H 210 −
= 0
− )pp(:H 211
0
13.148
)pp(:H 210 −
= 0
− )pp(:H 211
0
645.1zzz 05.==
13.149
)pp(:H 210 −
= 0
− )pp(:H 211
0
13.150
)pp(:H 210 −
= 0
− )pp(:H 211
0
13.151
)pp(:H 210 −
= 0
− )pp(:H 211
0
13.152a
)pp(:H 210 −
= 0
)pp(:H 211 −
> 0
b
2
22
1
11
2/21 n
)p
ˆ
1(p
ˆ
n
)p
ˆ
1(p
ˆ
z)p
ˆ
p
ˆ
(−
+
−
−
= (.2632–0741)
162
)0741.1(0741.
38
)2632.1(2632.
645.1 −
+
−
=.1891
.1223; LCL = .0668, UCL = .3114
13.153
)pp(:H 210 −
= 0
− )pp(:H 211
0
13.154
)pp(:H 210 −
= 0
− )pp(:H 211
0
13.155
)pp(:H 210 −
= –.02
− )pp(:H 211
–.02
13.156
)pp(:H 210 −
= 0
− )pp(:H 211
0
Rejection region:
05.
zzz =
= 1.645
2 = Success
There is not enough evidence to infer that those with more education are less likely to work 11 hours or more per
day.
13.157
)pp(:H 210 −
= 0
− )pp(:H 211
0
There is not enough evidence to infer that Americans are more dissatisfied with their jobs in 2011 than they were in
2008.
13.158
)pp(:H 210 −
= 0
− )pp(:H 211
05.
zzz =
13.159
)pp(:H 210 −
= 0
13.160
)pp(:H 210 −
= 0
− )pp(:H 211
0
13.161a
)pp(:H 210 −
= 0
− )pp(:H 211
0
p-value = P(Z > 2.50) = 1 – .9938 = .0062. There is enough evidence to conclude that members of segment 1 are
more likely to use the service than members of segment 4.
b
)pp(:H 210 −
= 0
− )pp(:H 211
0
Rejection region:
05.2/ zzz −=−
= –1.96 or
05.2/ zzz =
= 1.96
13.162
)pp(:H 210 −
= 0
− )pp(:H 211
0
13.163 H0: (p1–p2) = 0
H1: (p1-p2) ≠ 0
13.164 H0: (p1-p2) = 0
H1: (p1-p2) ≠ 0
13.165 H0: (p1-p2) = 0
H1: (p1-p2) < 0
13.166 H0: (p1-p2) = 0
H1: (p1-p2) > 0
13.167 H0: (p1-p2) = 0
H1: (p1-p2) < 0
13.168 H0: (p1-p2) = 0
H1: (p1-p2) > 0
13.169 H0: (p1-p2) = 0
H1: (p1-p2) < 0
13.170 H0: (p1-p2) = 0
H1: (p1-p2) ≠ 0
13.171 H0: (p1-p2) = 0
H1: (p1-p2) > 0
13.172 H0: (p1-p2) = 0
H1: (p1-p2) ≠ 0