a statistic representing how closely two variables co-vary; it can vary from -1 (perfect negative correlation) through 0 (no correlation) to +1 (perfect positive correlation) "what is the correlation between those two variables?" correlation coefficientcoefficient of correlationcorrelation
a statistical relation between two or more variables such that systematic changes in the value of one variable are accompanied by systematic changes in the other correlationcorrelational statistics