CORRELATION

Correlation is  the study of the  liner relationship  between  two variable when there is a  relationship of quantitative measures between two set  of variable  the appropriate statistical tool for measuring the relationship and expressing each in a precise way is known  as correlation. For  example  there is a relationship  between  the  heights and  weights of persons demand  and prices of  commodities etc.

According  to W.I. King Correlation  means  that between  two series or groups  of data  there exists  some  relationship  connections.

According to croxton and Cowden" The appropriate statistical   tool for  discovering and  measuring  the relationship of quantitative nature and expressing it in   brief  formula is known as correlation.

The coefficient  of correlation measures the degree  of relationship  between  two set  of figures. As  the reliability  of estimates depend upon the  closeness  of the relationship it is imperative that  utmost care be taken  while  interpreting the value of coefficient of correlation  otherwise fallacious conclusion can  be draw.