The coefficient of correlation is a number between -1 and 1 that indicates the strength and direction of the linear relationship between two variables. A value of 0 means no correlation, 1 means perfect positive correlation, and -1 means perfect negative correlation. The coefficient of correlation is calculated using Karl Pearson's method and is denoted by r. It is a dimensionless number that is unaffected by changes in scale or origin of the variables.

1. SUBMITTED BY
Shafeek.s

2. Coefficient of correlation is a pure number
lying between -1 and +1. When the
correlation is negative, it lies between -1 and
0.When the correlation is positive ,it lies
between 0 and 1. When the correlation is zero
,it indicates that there is no correlation and
when the correlation is 1,there is perfect
correlation.

3.  Karl Pearson’s method
 Spearman’s method
 Concurrent deviation method

4.  It is the widely used method
 It is also known as Pearsonian
coefficient of correlation.
 It is denoted by the symbol ‘r’.
 The formula can be expressed as

5. The degree of correlation can be
classified into three types and
they are:-
1. Perfect correlation
2. No correlation
3. Limited degree of correlation

6.  Correlation coefficient has a well defined
formula.
 Coefficient correlation is a pure number and
is independent of the units of measurement.
 It lies between -1 and +1.
 Correlation coefficient does not change with
reference to change of origin or change of
scale.

7.  Probable error of coefficient of correlation is a
statistical measure which measures reliability and
dependability of the value of coefficient of
correlation.
 If probable error is added or subtracted from the
coefficient of correlation, it would give two such
limits within which we can reasonably expect the
value of coefficient of correlation to vary.