1 Variance (Minitab): χ² test of H0 σ² = σ₀² (normal data) or Bonett's kurtosis-adjusted method (default in Minitab for non-normal data; Bonett 2006): CI exp[ln(c·s²) ± z·c·se₀], se₀² = (γ̂ − (n−3)/n)/(n−1), c = n/(n − z), γ̂ the kurtosis about a trimmed mean; p-value = smallest α whose interval excludes σ₀².
1 Variance (Minitab): χ² test of H0 σ² = σ₀² (normal data) or Bonett's kurtosis-adjusted method (default in Minitab for non-normal data; Bonett 2006): CI exp[ln(c·s²) ± z·c·se₀], se₀² = (γ̂ − (n−3)/n)/(n−1), c = n/(n − z), γ̂ the kurtosis about a trimmed mean; p-value = smallest α whose interval excludes σ₀².