Correlation coefficient tends to lie between ?

Ans. is 'b' i.e., -1.0 to + 1.0 There are two main type of correlation cofficients 1) Pearson's correlation cofficient o It is used in ungrouped series It measures the linear association between two variables that have been measured on interval or ratio scales, e.g. relationship between height (in inches) and weight (in pounds). It is used when the associated variables are jointly normally distributed. It is denoted by 'C. 2) Spearman correlation cofficient It used in grouped series o It is usually calculated on ocasions when it is not conveinient, economic or possible to give actual values to variables, but only to assign a rank order to instances of each variables. It may also be a better indicator that a relationship between two variables in non-linear. o It is used when two variables are not jointly normally distributed. o It is denoted by "rho (P)".