Compute the unrestricted variance of T.
Given reliability estimates in the population and in the sample, as well as the variance of X,
the unrestricted variance of T.
Ut(rxxi, rxxa, ux)
the reliability estimate of x in the incumbent (restricted) population
the reliability estimate of x in the applicant (unrestricted) population
The unrestricted variance of X
a value indicating the unresticted variance of T
Ut(.6, .8, 1.5)