Apps. and Interpretation for IBDP Maths Ebook 1 | Page 246

Your Practice Set – Applications and Interpretation for IBDP Mathematics
(a) (i) Write down the median number of hours worked by workers.
(ii) Write down the number of workers who worked 30 hours or less.
[3]
The city paid each of the workers $20 per hour for the first 30 hours worked, and $30 per
hour for each hour they worked after the first 30 hours.
(b)
Find the amount of money a worker earned for working
(i)
25 hours;
(ii)
35 hours.
(c) Find the number of workers who earned less than or equal to $200.
(d) Only 10 workers earned more than $k . Find the value of k .
The data above was obtained from a survey. A manager arranged the worker IDs in
ascending order and then asked every 10th worker on the list.
[4]
[3]
[4]
(e)
Identify the sampling technique used.
[1]
Solution
(a) (i) 20 hours A2 N2
(ii) 55 A1 N1
(b) (i) The amount of money
� (20)(25)
� $500
A1 N1
[3]
(c)
(ii)
The amount of money
� (20)(30) � (30)(35 � 30)
(M1)(A1) for correct formula
� $750
A1 N3
The number of working hours
200
�
20
(A1) for correct formula
� 10
Thus, the number of workers is 15. A2 N3
[4]
[3]
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