Question

The given table shows the ranking of ten students in two subjects mathematics and statistics.

Mathematics	Statistics
3	6
5	4
8	9
4	8
7	1
10	2
2	3
1	10
6	5
9	7

The coefficient of rank correlation is:

1. -0.3
2. -0.1
3. 0.1
4. 0.3

Answer 1

Correct Answer - Option 1 : -0.3

Formula used

r = 1 - (6Σd²)/n(n² - 1)

Calculation

Mathematics r1	Statistics r2	d = r1 – r2	d2
3	6	-3	9
5	4	1	1
8	9	-1	1
4	8	-4	16
7	1	6	36
10	2	8	64
2	3	-1	1
1	10	-9	81
6	5	1	1
9	7	2	4
Total			214

⇒ r = 1 - [6 × 214/10(10² - 1)]

⇒ r = 1 - 1.2969

∴ The coefficient of rank correlation is -0.2969 0r - 0.3