Apps. and Interpretation for IBDP Maths Ebook 1 | Page 234

Your Practice Set – Applications and Interpretation for IBDP Mathematics
Exercise 66
1. The table below shows the frequency distribution of the number of full stops in a
document of 80 pages:
Number of fullstops
Frequency
25 �x
� 30
18
30 �x
� 35
34
35 �x
� 40
11
40 �x
� 45
10
45 �x
� 50
7
(a) (i) Write down the class mark for the class 25 �x
� 30 .
(b)
(ii)
Write down the modal class.
Find an estimate for
[2]
(i)
the mean number of full stops, giving the answer in exact value;
(ii)
the standard deviation;
(iii)
the variance.
[4]
2. The table below shows the frequency distribution of the amount of money spent by 200
customers in an outlet store on a particular Sunday:
Amount of money (USD)
Frequency
0 �x
� 50
87
50 �x
� 100
55
100 �x
� 150
27
150 �x
� 200
11
200 �x
� 250
f
250 �x
� 300
5
(a) Find the value of f .
[2]
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