Example Calculate ‘ R ’ of 6 students from the following data.
Marks in Stats :

40

42

45

35

36

39

Marks in English :

46

43

44

39

40

43

Solution:
Marks in Stats

R_{1}

Marks in English

R_{2}

R_{1}  R_{2}

(R_{1} R_{2})^{2}
=D^{2}

40

3

46

1

2

4

42

2

43

3.5

1.5

2.25

45

1

44

2

1

1

35

6

39

6

0

0

36

5

40

5

0

0

39

4

43

3.5

0.5

0.25







N = 6




S D = 0

S D^{2} = 7.50

Here m = 2 since in series of marks in English of items of values 43 repeated twice.
Example The value of Spearman’s rank correlation coefficient for a certain number of pairs of observations was found to be 2/3. The sum of the squares of difference between the corresponding rnks was 55. Find the number of pairs.
Solution: We have

Index
6. 1 Introduction
6. 2 Correlation
6. 3 Types of Correlation
6. 4 Degrees of Correlation
6. 5 Methods of determining correlation
6. 6 Coefficients of Correlation for Bivariate
Grouped Data
6. 7 Probable Error
6. 8 Rank Correlation Coefficient
6. 9 Linear Regression
Chapter 7
