A food scientist wishes to estimate the variability in fiber content (in grams per serving) of a new high‑fiber breakfast cereal. A simple random sample of $n=36$ servings yields a sample standard deviation of $s=1.20$g. Assuming fiber content is normally distributed, using a $99\%$ confidence level, determine the degrees of freedom, the critical values ${\chi }_L^2$ and ${\chi }_R^2$, and the confidence interval estimate (up to two decimal places) for the population standard deviation $\sigma$.