# Question: Let S2 be the variance of a random sample of

Let S2 be the variance of a random sample of size n from N(μ, σ2). Using the fact that (n − 1)S2/σ2 is χ2(n−1), note that the probability

Where

Rewrite the inequalities to obtain

If n = 13 and

Show that [6.11, 24.57] is a 90% confidence interval for the variance σ2. Accordingly, [2.47, 4.96] is a 90% confidence interval for σ.

Where

Rewrite the inequalities to obtain

If n = 13 and

Show that [6.11, 24.57] is a 90% confidence interval for the variance σ2. Accordingly, [2.47, 4.96] is a 90% confidence interval for σ.

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