Apps. and Interpretation for IBDP Maths Ebook 1 | Page 233

66
Paper 1 – Frequency Tables of Continuous Data
Example
The table below shows the frequency distribution of the heights of 60 students:
Height (cm)
Frequency
140 �x
� 150
5
150 �x
� 160
10
160 �x
� 170
17
170 �x
� 180
25
180 �x
� 190
3
17
(a) (i) Write down the class width for the class 140 �x
� 150 .
(b)
(c)
(ii) Write down the class mark for the class 160 �x
� 170 .
State whether the data is discrete or continuous.
Find an estimate for
[2]
[1]
(i)
the mean height;
(ii)
the standard deviation;
(iii)
the variance.
[4]
Solution
(a) (i) 10 cm A1 N1
(ii) 165 cm A1 N1
(b) Continuous A1 N1
(c) (i) 167 cm A2 N2
[2]
[1]
(ii) 10.4 cm A1 N1
(iii) 108 cm A1 N1
[4]
223
www.seprodstore.com