# EXAM REVIEW CORRELATION COEFFICIENT

## Document Summary

Tells us the strength of the relationship between x and y. The average product of z-scores same thing as z scores. Correlation coefficients are the covariance when there are standard variables standardize x but leave y and its use get a measure in y units. Covxy = a measure of the relation between x and y the covariance standardized by the standard deviation of x and y. To standardize , we divide the covariance by the size of the standard deviations. G iven that the maximum value of the covariance is plus or minus the product of the variance of x and the variance of y, it follows that the limits on the correlation coefficient are +1. 0 or 1. 0. The correlation coefficient is not an unbiased esimator. If the regression coefficient is computed the slopes can be he same but the correlation is different i. e. the second scatterplot has more noise. 8 r a r a j j d d.