Internal function to compute Raju and Burke's correction for univariate direct range restriction
.correct_r_rb(rxyi, qx = 1, qy = 1, ux = 1)
A vector of corrected correlations.
Vector of observed 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.