Internal function to attenuate correlations using Raju and Burke's formula for univariate direct range restriction
.attenuate_r_rb(rtpa, qx = 1, qy = 1, ux = 1)
Vector of fully corrected correlations.
Vector of square-root of reliability coefficients for X.
Vector square-root of reliability coefficients for Y.
Vector of observed-score u ratios for X.
A vector of corrected correlations.