Propose a pivotal quantity to construct the confidence interval. Please see problem below.

A sample was drawn from each of five populations assumed to be normally distributed with the same variance, 02. The values of the sample variances, 52, and sample sizes, n, were: 52: 40 30 20 42 50 n:6 4 3 7 8 ___ 2 Take note that 52 = 221:) . (a) Propose a pivotal quantity that can be used in the construction of the confidence interval for the common variance 02 and state the distribution of the proposed pivotal quantity