Comparison of best-fit theoretical and simulated angular power spectra for BINGO frequency channels. The blue solid curve shows the best-fit theoretical angular power spectrum (S_L) derived from the optimal cosmological and hydrogen intensity (HI) parameters. Orange points represent simulated BINGO data, including contributions from white noise and foreground removal. Error bars indicate the 1σ uncertainty on S_L, computed as the standard deviation across 3000 mock realizations. For each frequency channel, the number of data points (N_d) and the reduced χ² statistic (χ²/N_d) are provided to quantify the agreement between theory and simulation.