Apps. and Interpretation for IBDP Maths Ebook 1 | Page 392

Your Practice Set – Applications and Interpretation for IBDP Mathematics
97.4 (a) H
0
: The age of staffs and
their number of investment
bank accounts are
independent
(b) x � 5, y � 4
(c) 8
(d) p-value � 0.326
(e)
Exercise 98
The null hypothesis is not
rejected as p-value � 0.05
98.1 (a) The lengths of fishes are
normally distributed
(b) (i) H
0
: �1 � �2
(ii) H
1
: �1 � �2
(c) p-value � 0.0800
(d)
The null hypothesis is not
rejected as p-value � 0.05
98.2 (a) The volumes of bottles of
milk are normally distributed
(b) (i) H
0
: �D � �L
(ii) H
1
: �D � �L
(c) p-value � 0.0300
(d)
The null hypothesis is
rejected as p-value � 0.05
98.3 (a) H
1: �1 � �2
(b) p-value � 0.0276
(c) � 2.09
(d) The null hypothesis is
rejected as p-value � 0.05
98.4 (a) H
1: �1 � �2
(b) p-value � 0.906
(c) � 0.120
(d) The null hypothesis is not
rejected as p-value � 0.1
Exercise 99
99.1 (a) (i) H
0
: The punctuality
of buses and the
locations of bus stops
are independent
(ii) H
1
: The punctuality
of buses and the
locations of bus stops
are not independent
(b) 3
(c)
(d)
� � 6.41
2
calc
The null hypothesis is
2
rejected as � � 6.251
calc
(e) (i)
1
5
(ii)
3
20
(iii)
19
85
(f)
119
165
99.2 (a) (i) H
0
: The number of
free lunches offered
and the positions of
staffs are independent
(ii) H
1
: The number of
free lunches offered
and the positions of
staffs are not
independent
(b) 9
(c)
p-value �5.95�
10
�7
(d) 46.0
(e) The null hypothesis is
rejected as p-value � 0.05
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