2. A simple random sample of sizen is drawn from a population that is known to be normally distributed. The sample variance, s´, is determined to be 12.2. Complete parts (a) through (c). (a) Construct...

Extracted text: 2. A simple random sample of sizen is drawn from a population that is known to be normally distributed. The sample variance, s´, is determined to be 12.2. Complete parts (a) through (c). (a) Construct a 90% confidence interval for o if the sample size, n, is 20. The lower bound is (Round to two decimal places as needed.)