Product moment coefficient of correlation measures which particular type of relationship between two variables?

Solution (By Examveda Team)

Product moment coefficient of correlation measures Circular type of relationship between two variables.
It is a measure of linear correlation between two sets of data. It is the ratio between the covariance of two variables and the product of their standard deviations; thus, it is essentially a normalized measurement of the covariance, such that the result always has a value between -1 and 1.
For variables X = {x₁,...,x_n} and Y = {y₁,...,y_n} that are defined on the unit circle [0, 2π), it is possible to define a circular analog of Pearson's coefficient. This measure can be useful in fields like meteorology where the angular direction of data is important.