Apps. and Interpretation for IBDP Maths Ebook 2 | Page 355

Answers
Exercise 73
73.1
( a )
( i )
1050 USD
( ii )
810 USD
( iii )
450 USD
( b )
SSres
33900
( c )
87.2 % of the variability of
the data is explained by
the regression model .
73.2
( a )
( i )
74.6625 marks
( ii )
78.9625 marks
( iii )
74.0625 marks
( b )
SSres
131
( c )
63.2 % of the variability of
the data is explained by
the regression model .
73.3
( a )
( i )
9231
( ii )
7200
( iii )
11264
( b )
SSres
60000
( c )
Model 1
73.4
( a )
( i )
212
( ii )
192
( iii )
155
( b )
SSres
2080
( c )
Model 2
Exercise 74
74.1 ( a ) ( i ) y � 0.00867x
3
2
3.92x �590
�29500 ( ii ) 59.9 kg
( b )
( i )
2 R �
0.967
( ii )
96.7 % of the variability of the data is explained by the regression model .
x
74.2 ( a ) ( i ) y�
23.8x
( ii ) 24.7 g
0.169
( b )
( i )
2 R �
0.360
( ii )
36.0 % of the variability of the data is explained by the regression model .
74.3
( a )
( i )
2 y � 0.25x �
2.25x �
1
( ii )
2 R �
0.967
( b )
SS
1
res
( c ) SStot
� 30.0 74.4 ( a ) ( i ) y �2.37 � 1.36 x
( ii )
2 R �
0.99957
( b )
SSres
0.0136
( c ) SStot
� 31.6
Chapter 19
Exercise 75
75.1
( a )
H
0
: The data follows a
Poisson distribution with mean 2 .
( b )
17.1
( c )
4
( d )
55.1
( e )
The null hypothesis is
2 rejected as
� 7.779
.
calc
75.2
( a )
H
0
: The data follows a
Binomial distribution with
parameters B ( 5 , 0.6 ) .
( b )
( i )
1.024
( ii )
4
( c )
24.8
( d )
The null hypothesis is
2 rejected as
� 9.488
.
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