Page 2 - Home assignment-correlation analysis.

4 12 16 144 48

5 10 25 100 50
6 08 36 64 48
=21 =78 2 2 =238
= 91 = 1084

− .
=
2
2
2
− ( ) − ( ) 2
6×238−21×78
 =
2
6×91−21 6×1084−78 2
1428−1638
 =
546−441 6504−6084
−210 −210
 = = = −1
105×420 210
There exists a perfect negative correlation between x and y.

Short cut method to measure coefficient of correlation: -

When data size is large and is in fraction then we apply the short-
cut method to easily calculate coefficient of correlation.

−

=
2
2
2
− ( ) − ( ) 2

Example-3: - Calculate the coefficient of correlation between the ages of husband
and the ages of wives.
Age of husband 24 25 22 30 34 37
Age of wife 20 21 18 26 28 30
Solution: - Calculation of coefficient of correlation

Let the age of husband be x and wife be y

2
2
X Y ×

24 20 -6 -6 36 36 36
25 21 -5 -5 25 25 25
22 18 -8 -8 64 64 64