Q.If the values of two variables move in opposite direction then the correlation is said to be :

Pearson's $r=\sum(x-\bar x)(y-\bar y)/\sqrt{\sum(x-\bar x)^2\sum(y-\bar y)^2}$ (or the equivalent direct-method formula) is a unit-free number between $-1$ and $+1$ measuring the strength and direction of the …