Consider the foam data in Exercise 10-18. Construct the following:
(a) A 90% two-sided confidence interval on σ2/1 σ2/2
(b) A 95% two-sided confidence interval on σ2/1 σ2/2. Comment on the comparison of the width of this interval with the width of the interval in part (a).
(c) A 90% lower-confidence bound on σ1/ σ2.