|
Q. 2. Calculate the correlation coefficient
for the following data: (June
2001)
| x |
y |
|
15 |
9 |
|
10 |
12 |
|
5 |
18 |
|
12 |
10 |
|
17 |
5 |
|
18 |
2 |
Solution.
| x |
y |
x2 |
y2 |
x X y |
|
15 |
9 |
225
|
81
|
135
|
|
10 |
12 |
100
|
144
|
120
|
|
5 |
18 |
25
|
324
|
90
|
|
12 |
10 |
144
|
100
|
120
|
|
17 |
5 |
289
|
25
|
85
|
|
18 |
2 |
324
|
4 |
36
|
|
å x = 77
|
å y = 56
|
å
x2 = 1107 |
å
y2 = 678 |
å
xy = 586 |
Here, n = 6
| |
|
[n å
xy - (å x X
å y)]
|
| r = |
|
|
| |
|
{[n å
x2 - (å
x)2] X [n å
y2 - (å
y)2]}
|
| |
|
[(6 X 586) - (77 X 56)]
|
| or r = |
|
|
| |
|
{[(6 X 1107) - (77)2]
X [(6 X 678) - (56)2]}
|
or r = - 0.976
|
