The value of the correlation coefficient r is useful indicator of the strength of an association between two variables when 1) one variable is numerical and the other is nominal
2) both variables are categorical
3) both variables are numerical and the association is linear
4) one variable is nominal and the other ordinal
5) none of the above

can i know which language is this?

yes they are the same

step-by-step explanation:

consider the parallelogram shown in the attached image.

in the parallelogram hijk, the length of hk is given as,

from the properties of parallelogram we know that the opposite sides of a parallelogram are parallel to each other and are equal in measure.

therefore, the length of the side ij must be equal to the length of the side hk and that is .

hence, the expression for the length of ij confirms that hijk is a parallelogram.