You work for a soft-drink company in the quality control division. You are interested in the standard
deviation of one of your production lines as a measure of consistency. The product is intended to
have a mean of 12 ounces, and your team would like the standard deviation to be as low as
possible. You gather a random sample of 15 containers. Estimate the population standard
deviation at a 80% level of confidence. 11.92 11.89 11.95 11.91 12.05 11.78 11.99 12.04 12.03
11.83 11.96 11.96 12.17 11.93 11.79 (Data checksum: 179.2) a) Find the sample standard
deviation: .103 Correct Round to 3 decimal places. b) Find the lower and upper critical values at
80% confidence: Round to 3 decimal places. Lower: Upper: c) Report your confidence interval for :
( , ) Round to 2 decimal places.