Question

A random sample of n = 11 observations was selected from a normal population. The sample...

A random sample of n = 11 observations was selected from a normal population. The sample mean and variance were x = 3.93 and s2 = 0.3216. Find a 90% confidence interval for the population variance σ2. (Round your answers to three decimal places.)

Homework Answers

Answer #1

Chi-square critical values at 0.10 significance level with 10 df = 3.940 , 18.307

90% confidence interval for 2is

(n-1) S2 / /2 <  2< (n-1) S2 / 1-/2

(11-1) * 0.3216 / 18.307 < 2< (11-1) * 0.3216 / 3.940

0.176 < 2< 0.816

90% CI is (0.176 , 0.816)

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