Apps. and Interpretation for IBDP Maths Ebook 1 | Page 244

Your Practice Set – Applications and Interpretation for IBDP Mathematics
2. There are 12 items in a data set. The mean of the items is 9.
(a)
Find the sum of the items.
The variance of this data set is 2.25. Each value in the set is added by 10.
[2]
(b) (i) Write down the value of the new mean.
(ii)
Find the value of the new standard deviation.
[3]
3. There are 16 items in a data set and arranged in ascending order. The 12th item and the
13th item are 20 and 22 respectively.
(a)
Find the upper quartile.
The lower quartile of this data set is 10. Each value in the set is multiplied by 4.
[2]
(b) (i) Write down the value of the new lower quartile.
(ii)
Find the value of the new inter-quartile range.
[3]
4. There are 25 items in a data set and arranged in ascending order. The 6th item and the 7th
item are 8 and 12 respectively.
(a)
Find the lower quartile.
The inter-quartile range of this data set is 19. Each value in the set is added by 5.
[2]
(b) (i) Write down the value of the new inter-quartile range.
(ii)
Find the value of the new upper quartile.
[3]
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