Appendix A.31
Variance/Std Dev CI Calculator
Construct confidence intervals for population variance and standard deviation using chi-square.
χ² Confidence Interval Calculator for σ² and σ
Important: This method requires the population to be normally distributed. Chi-square confidence intervals are not robust to departures from normality.
Chi-Square Critical Values (df = 24)
12.4010
39.3640
95% CI for Population Variance (σ²)
(10.7550, 34.1392)
Sample variance s² = 17.6400
95% CI for Population Std Dev (σ)
(3.2795, 5.8429)
Sample std dev s = 4.2000