Where \(\bar x\) is the observed mean, \(e\) is the expected value, \(s\) is the sample standard deviation, \(n\) is the sample size, and \(d_{eff}\) is Extra deff:
\[\begin{align} z = \sqrt{n/d_{eff}}\frac{\bar x - e}{s} \end{align}\]
where \(p = 2(1-\Phi(|z|))\) if \(\bar x \ne e\) and NaN otherwise.