The Wilkinson Microwave Anisotropy Probe (WMAP) observations provide precise data that enable a thorough test of cosmological models. The emerging standard model, a flat Λ-dominated universe with nearly scale-invariant adiabatic Gaussian fluctuations, fits the WMAP data well. The best-fit parameters are \( h = 0.72 \pm 0.05 \), \( \Omega_b h^2 = 0.024 \pm 0.001 \), \( \Omega_m h^2 = 0.14 \pm 0.02 \), \( \tau = 0.166 \pm 0.076 \), \( n_s = 0.99 \pm 0.04 \), and \( \sigma_8 = 0.9 \pm 0.1 \). These parameters are consistent with other astronomical measurements, such as stellar ages, the baryon/photon ratio, and the Hubble constant. By combining WMAP data with other datasets, such as the 2dF Galaxy Redshift Survey and Lyman α forest data, the best-fit cosmological parameters are refined to \( h = 0.71_{-0.03}^{+0.04} \), \( \Omega_{\mu} h^2 = 0.0224 \pm 0-cm^2 \), \( \Omega_m h^2 = 0.135_{-0.009}^{+0.008} \), \( \tau = 0.17 \pm 0.06 \), \( n_s(0.05 \ \text{Mpc}^{-1}) = 0.93 \pm 0.03 \), and \( \sigma_8 = 0.84 \pm 0.04 \). The WMAP detection of early reionization rules out warm dark matter. The analysis also constrains the geometry of the universe, the equation of state of dark energy, and the energy density in neutrinos.The Wilkinson Microwave Anisotropy Probe (WMAP) observations provide precise data that enable a thorough test of cosmological models. The emerging standard model, a flat Λ-dominated universe with nearly scale-invariant adiabatic Gaussian fluctuations, fits the WMAP data well. The best-fit parameters are \( h = 0.72 \pm 0.05 \), \( \Omega_b h^2 = 0.024 \pm 0.001 \), \( \Omega_m h^2 = 0.14 \pm 0.02 \), \( \tau = 0.166 \pm 0.076 \), \( n_s = 0.99 \pm 0.04 \), and \( \sigma_8 = 0.9 \pm 0.1 \). These parameters are consistent with other astronomical measurements, such as stellar ages, the baryon/photon ratio, and the Hubble constant. By combining WMAP data with other datasets, such as the 2dF Galaxy Redshift Survey and Lyman α forest data, the best-fit cosmological parameters are refined to \( h = 0.71_{-0.03}^{+0.04} \), \( \Omega_{\mu} h^2 = 0.0224 \pm 0-cm^2 \), \( \Omega_m h^2 = 0.135_{-0.009}^{+0.008} \), \( \tau = 0.17 \pm 0.06 \), \( n_s(0.05 \ \text{Mpc}^{-1}) = 0.93 \pm 0.03 \), and \( \sigma_8 = 0.84 \pm 0.04 \). The WMAP detection of early reionization rules out warm dark matter. The analysis also constrains the geometry of the universe, the equation of state of dark energy, and the energy density in neutrinos.