Where \(g_1\) and \(g_2\) are the two proportions, \(m\) and \(n\) are their sample sizes, and \(se_1\) and \(se_2\) are their standard errors:
\[\begin{align} t=\frac{g_1-g_2}{\sqrt{d_{eff}(se^2_1 + se^2_2)}} \end{align},\]
where:
\(sp = 2\Pr(t_v \ge |t|),\)
\(v = \frac{(se^2_1 +se^2_2)^2}{\frac{se^4_1}{n-b}+\frac{se^4_2}{m-b} }\) or, if Weights and significance is set to Un-weighted sample size in tests (see Weights, Effective Sample Size and Design Effects), \(v = n + m - 2\)
\(b\) is 1 if Bessel's correction is selected for Proportions in Statistical Assumptions and 0 otherwise.
\(d_{eff}\) is Extra Deff (see Weights, Effective Sample Size and Design Effects).