Internal function to undo the Case IV correction for univariate indirect range restriction
.attenuate_r_uvirr(rtpa, qxi = 1, qyi = 1, ut = 1)
A vector of attenuated correlations.
Vector of fully corrected correlations.
Vector of square-root of incumbent reliability coefficient for X.
Vector of square-root of incumbent reliability coefficient for Y.
Vector of true-score u ratios for X.