Suppose that you have n=400 data values and suppose you have computed from those a sample variance of \(s^2 = 479.5\text{.}\) Then, the only change in the calculation is the two chi-square statistic values. For 95% but now with 399 degrees of freedom \(\chi_{0.025}^2 = 345.55\) and \(\chi_{0.975}^2 = 456.24\text{.}\)