Question
Calculate Karl pearson’s co-efficint of correlation with the help of following data.
|
X |
6 |
8 |
12 |
15 |
18 |
20 |
24 |
18 |
31 |
|
Y |
10 |
12 |
15 |
15 |
18 |
25 |
22 |
26 |
28 |
Solution
Calculation of Pearson’s co-efficient of correlation
|
X |
X'(X-8) |
X2 |
Y |
Y =(Y-19) |
Y2 |
XY |
|
|
6 |
–12 |
144 |
10 |
–9 |
81 |
+108 |
|
|
8 |
–10 |
100 |
12 |
–7 |
49 |
+70 |
|
|
12 |
–6 |
36 |
15 |
–4 |
16 |
+24 |
|
|
15 |
–3 |
9 |
15 |
–4 |
16 |
+12 |
|
|
18 |
0 |
0 |
18 |
–1 |
1 |
0 |
|
|
20 |
+ 2 |
4 |
25 |
+ 6 |
36 |
+12 |
|
|
24 |
+ 6 |
36 |
22 |
+ 3 |
9 |
+18 |
|
|
18 |
+ 10 |
100 |
26 |
+ 7 |
49 |
+70 |
|
|
31 |
+ 13 |
169 |
28 |
+ 9 |
81 |
+117 |
|
|
ΣX = 162 |
XX = 0 |
ΣX2 = 598 |
ΣY= 171 |
Σ Y= 171 |
Σ Y2 = 338 |
Σ XY= 431 |
