Apps. and Interpretation for IBDP Maths Ebook 1 | Page 333

Exercise 94
1. 100 customers completed the survey about their feedbacks on five different types of ice
cream of different selling prices. The following table shows the overall rankings of five
different types of ice cream based on the feedbacks and the corresponding selling prices,
where 1 represents the highest rank and 5 represents the lowest rank:
Brand A B C D E
Ranking 5 2 4 1 3
Selling price $10 $12 $7 $20 $13
(a)
(b)
(c)
Explain why it is not appropriate to use the product moment correlation
coefficient for the above table.
Find the Spearman’s rank correlation coefficient for the above data set.
Comment on the conclusion of the result in (b).
[1]
[2]
[1]
2. The following table shows the scores of a Geography test and a Chemistry test of eight
students, both out of 100:
Student A B C D E F G H
Geography 90 71 60 55 53 50 49 54
Chemistry 20 30 35 40 50 45 65 70
(a)
(b)
(c)
Explain why it is not appropriate to use the product moment correlation
coefficient for the above table.
Find the Spearman’s rank correlation coefficient for the above data set.
Comment on the conclusion of the result in (b).
[1]
[2]
[1]
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