First (purple), second (green), and third (orange) moments plotted as a function of f_NL for the same s bins as in Fig. 2. Each point represents the average moment computed from the 125 FastPM-L1 simulations at f_NL = −25, 0, and 25, comprising the observation vector, ${\widehat{\mu }}_i$ (with each moment plotted separately). Dashed lines indicate the quadratic fit; i.e., the expectation vector ${\stackrel{\sim }{\mu }}_i(f_{\text{NL}})$. The f_NL = 12 test case is shown as a red star, with error bars representing the standard error on μ across the 125 simulations.