Let \(X_1,\ldots ,X_n\) be iid Uniform\((0,\theta )\) with \(\theta >0\), and \(X_{(n)}\) be the largest order statistic.
(a) Find the probability that the random interval \((X_{(n)},2X_{(n)})\) contains \(\theta \).
(b) Find the constant \(c\) such that \((X_{(n)},cX_{(n)})\) is a \(100(1-\alpha )\%\) confidence interval for \(\theta \).