Question

Covariance is

		the average distance scores deviate from the mean.
		a dimensionless index of the relationship between X and Y.
		the distance between the real and hypothesized means.
		the average cross-product.

Answer 1

Here' the answer to the question. please write back in case you've doubts.

Covariance indicates the direction of the linear relationship between variables. Covariance is the measure of the joint variability of two random variables. If the greater values of one variable mainly correspond with the greater values of the other variable, and the same holds for the lesser values, the covariance is positive.

Hence, It is => a dimensionless index of the relationship between X and Y

2nd option is correct